United States Department of Agriculture Baho de Oro Natural Area Forest Service Luquillo Mountains, Southern Forest Experiment Station New Orleans, General Technical Report Peter L. Weaver SO-111 September 1994 The 745-ha Bano de Oro Natural Area, established by the U.S. Department of Agriculture, Forest Service, in 1949, was made part of the Luquillo Experimental Forest Biosphere Reserve in 1976. The Natural Area, situated at elevations between 245 and 1,025 m in the wettest part of Puerto Rico, encompasses four major forest types that are free of human disturbance. Past and current research in the Bafio de Oro Natural Area is summarized in this document to serve as a basis for further investigation. The current state of knowledge regarding the environment (i.e., geology, phys- iography, soils, climate, hydrology, flora, and fauna) is outlined.

The author is grateful to numerous researchers for assistance in the comple- tion of this report. Manuel Velez and his graduate students conducted the survey of the fauna in the Bafio de Oro. James A. Ackerman, Ned Fetcher, Charlotte M. Taylor, Janice Voltzow, Lawrence R. Walker, and Sandra Guzman of the Univer- sity of Puerto Rico Biology Department as well as Clyde E. Asbury, D. Jean Lodge, William T. Lawrence, John A. Parrotta, and Robert B. Waide of the Center for Energy and Environment Research (CEER) provided information for the ongoing Minority Research Program in the dwarf forest near the Baiio de Oro. Several others provided information on specific topics: Clyde E. Asbury, stream sampling; Sonia Borges, University of Puerto Rico, Mayaguez, earth- worms; Allan Drew, State University of New York, College of Forestry and Environmental Science, ring formation in C~rillaracemiflora; Miguel A. Garcia, University of Puerto Rico, Rio Piedras, anoline lizards; Rafael Joglar, University of Puerto Rico, Rio Piedras, frog density and diversity; and Joe Wunderle, International Institute of Tropical Forestry, data from the phenology trail. Loren Huffaker of the Carribean National Forest devised an updated classification of the soils. Russell M. Burns, U.S. Department of Agriculture, Forest Service, Washington Office, and Margaret S. Devall, U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station, New Orleans, reviewed the entire document. This study was made possible by a grant from the United States Man and the Biosphere (MAB) program. The collaboration of the Univer- sity of Puerto Rico is recognized.

Cover: Overview of Bafio de Oro Natural Area from the Yokahu Tower BACKGROUND INFORMATION ...... 1 Introduction ...... 1 Administrative Details ...... 2 Historical Perspective ...... 2 Objectives ...... 3 OVERVIEW OF MAJOR FOREST RESEARCH ...... 3 THE B~ODE OR0 NATURAL AREA ...... 4 Geology ...... 4 Physiography ...... 6 Soils ...... 7 Climate ...... 8 Precipitation ...... 10 Temperature ...... 10 Relative Humidity ...... 11 Wind Velocity and Direction ...... 11 Cloud Cover and Solar Insolation ...... 11 Hurricanes ...... 12 Hydrology ...... 13 FLORA ...... 13 Major Forest Qpes ...... 13 Other Vegetation Qpes ...... 14 Distribution ...... 14 Pico del Oeste Flora ...... 14 Vascular ...... 14 Mosses ...... 19 Leafy Hepaticae ...... 19 Algae ...... 19 Other Dwarf Forest Studies ...... 19 Vegetation Gradient ...... 29 Current Research Activities ...... 31 Long-term Monitoring on TR-I ...... 31 Phenology Trail ...... 37 Ring Formation in Cyrilla racemiflora ...... 37 Minority Research Program ...... 37 Water Chemistry ...... 38 FAUNA ...... 39 Vertebrates ...... 39 Bat Study ...... 44 Black Rat Study ...... 44 Puerto Rican Parrot Studies ...... 45 Other Species Studies ...... 46 Anoline Lizard Studies ...... 46 Frog Diversity Study ...... 47 Invertebrates ...... 47 Earthworm Study ...... 47 Studies of Other Organisms ...... 47 Classified and Species ...... 47 FUTURE ACTIVITIES ...... 47 LITERATURE CITED ...... 48 APPENDIXTABLE 1 ...... 55 Bdo de Oro Natwd Area Luquillo sins herto Rico Peter L. Weaver

INFORrnTION The purpose of this report is to compile relevant environmental information on the Baiio de Oro Research Natural Area (Baiio de Oro) in Puerto Rico. Introduction. Because research in the Luquillo Mountains has been extensive, much of the data was derived from published Research Areas (RNA's) are tracts On which sources. Original inventories of fauna and flora, how- natural features and processes predominate and which ever, have been included to complement other informa- are preserved for scientific or educational purposes tion. Subsequent research will undoubtedly result in (Federal Committee On Research Natural 1968)' the identification of additional species and will require The areas need not be pristine because this requisite supplements to this text. would preclude many ecosystems that have suffered some live1 of human disturbance and which no longer exist in an undisturbed state (Dyrness and others 1975). I-Iowever, if disturbed ecosystems are designated as RNA's, protective measures should be undertaken to restore them to their original condition through natu- ral processes. Research Natural Areas may vary in size from a few to several thousand hectares and preferably are surroundedtd,or buffered, by other protected land. Research Natural Areas are established to provide a baseline for comparison with areas influenced by human activity (Moir 1972). Research Natural Areas may include typical or unusual fauna and flora or may represent outstanding geologic, pedologic, or aquatic features or processes. They constitute reserves for the protection of rare or endangered organisms and serve as reservoirs for the conservation of genetic resources. Research on RNA's must be essentially nonmanipula- tive and reasonably consistent with the purpose and character of the surrounding land (Federal Committee on Research Natural Areas 1968). Deliberate manipula- tion simulating natural processes is occasionally allowed and, in some instances, encouraged to restore communities or organisms to their original state (Dyrness and others 1975). It is imperative that the U.S. Department of Agricul- ture, Forest Service, exercise control over all research activities to assure that they comply with existing guidelines and do not negatively impact the resources in the RNA. The Forest Service must grant permission for all research activities and review them regularly. Research Natural Areas managed under the above widelines serve scientists, resource managers, and the

level. Area.

Peter L. Weaver is a research forester at the International Institute of Tropical Forestry, U.S. Department of Agriculture, Forest Service, Rio Piedras, PR 00928-2500. In cooperation with: University of Puerto Rico, Rio Piedras, PR 00936-4984. Administrative Details Rio de la Mina at a 450-m elevation. From this point, the boundary is the Rio de la Mina to its confluence At the end of the Spanish-American War in 1898, the with the Rio Mameyes. A primitive trail parallels the Crown lands of Puerto Rico passed from Spain to the Rio de la Mina and terminates at the Rio Mameyes. The United States. In 1903, the United States government northeastern boundary is the Rio Mameyes and its proclaimed these lands as the Luquillo Forest Reserve, eastern fork for nearly half its distance after which the and since 1917 they have been managed by the Forest boundary follows along a ridge to a local high point at Service. In 1935, the Luquillo Forest Reserve was an elevation of 675 m and then descends along a divide renamed the National Forest (CNF) to to the Rio Fajardo. About 90 percent of the south- include Federally purchased lands elsewhere in Puerto eastern boundary is the eastern tributary of the Rio Rico. In 1939, the 'I'ropical Forest Experiment Station Fajardo from its confluence with the Rio Fajardo to its (now the International Institute of Tropical Forestry) source just below Pico del Oeste. The remainder of the was established. In 1956, the CNF was also admin- boundary follows the ravine above the river to Pico del istratively designated as the Luquillo Experimental Oeste. Forest (LEF) to recognize the growing importance of Expansion of the Baiio de Om by more than 40 research in the forest. Although the terms CNF and percent to encompass a total of 1,180 ha is being consid- LEF refer to the same land, the objectives of the Forest ered in the current forest management plan. The pro- Service units that work in the forest are distinct. The posed new areas include Pico del Este, one of the CNF is responsible for management of the forest, or wettest locales on the Island, areas above a 750-m making it productive by demonstrating forest practices elevation east of Pico del Este, and areas above a 700-m in a tropical setting. The LEF is responsible for far- elevation south of the road to Pico del Este (fg.1). A estry and forest-related ecological research. Through- small area known locally as the "valley of the giants" out this publication this area will be referred to as the because of the many large found there is also part LEF. of the proposed addition. It extends down to a 640-m The 745-ha Baiio de Oro (located at 18°17'30wN. elevation in the Icacos Valley, south of the Pico del Este latitude and 65"45'3OWFV. longitude) in the Luquillo road. Mountains (fig. 1) was established by the Forest Ser- vice in 1949. Although comparatively small in size, the Historical Perspective Baiio de Oro encompasses the boundary areas of four municipalities: Rio Grande, Luquillo, Fajardo, and Land clearing by pre-Columbian Indians appears to Ceiba. have affected only a small area in Puerto Rico, mainly The Baiio de Oro was selected as an RNA for several on the coastal plain Wadsworth 1950a). Land clearing reasons: (I) the land was surrounded by other Forest by settlers began early in the northeastern part of the Service lands, (2) the terrain was unmodified by Island but did not ascend the slopes of the Luquillo human activity, (3) the unit contained representative Mountains for many years because Carib Indians lived areas of the four forest types that characterize the there. Before 1876, the Spanish Crown did not grant Luquillo Mountains, and (4) the unit contained popula- concessions to people willing to settle in the mountains. tions of the endemic Puerto Rican parrot (Amazona In 1876, the Crown established forest reserves in vittata), at that time confined to the upper slopes of the Puerto Rico, including the LEF (Brown and others Luquillo Mountains. Since its proclamation, the Baiio 1983). Subsequently, concessions to some mountainous de Oro has been managed in accordance with RNA lands were granted, but inaccessibility and the poor guidelines. In 1968, it was listed in a national directory quality of the soil caused the core of the Luquillo of more than 300 RNA's set aside on Federal lands Mountains to remain Crown land and to remain for- (Federal Committee on Research Natural Areas 1968). ested until the Treaty of Paris in 1898. In 1903, conser- In 1976, the entire LEF was designated as part of the vation of the region began with the proclamation of the international network of Biosphere Reserves (Lugo Luquillo Mountains as a forest reserve. 1987). The search for gold in the Luquillo Mountains was The Baiio de Oro is roughly diamond shaped and carried on from 1513 until the late 19th century oriented in line with the cardinal directions (fig. 1).The Wadsworth 1950a, 1970). During the 19th century, southwestern boundary extends along the ridge from gold was discovered near the confluence of the Rio de la the intersection of the Molindero and Pico del Este Mina and Rio Mameyes where the Luquillo Mine and Roads to Pico de1 Oeste, approximately paralleling the the Monserrate Mine operated for a few years (Cardona Pic0 del Este Road, which was finished in 1962. The 1984, Cox and Briggs 1973). Penetration into the upper lower half of the northwestern boundary is about slopes of the Luquillo Mountains via foot trails, how- 100 m east of the Molindero Road. Where the northern ever, was infrequent as late as 1905 (Wadsworth 1970). part of the Molindero Road trends west, the boundary The foot trail to El Yunque was virtually impassable continues northeast on the same ridge intersecting the until a horse trail was finished in 1922. Route 191 from ROUTE ROUTE 186 191

EL VERDE

NATURAL AREA

ROUTE PROPOSED BOUNDARY EXPANSION OF NATURAL

* EL VERDE FIELD STATION ROUTE A STREAM GAUGING STATION 0 I2km 191 - C -119 WRECK u

Figure 1.- Location of the Bario de Om Natural Area within the Luquillo Experimental Forest. Climatic stations and reference sites are indicated.

the town of Mameyes to Rio Blanco, initiated in 1926, review it in detail. Research activities conducted within was not completed until 1942. Only 7 years later, the the Baiio.de Oro are emphasized along with relevant Forest Service established the Baiio de Oro, located ecological information gathered in the surrounding for- about 1km east of the highway. At that time, less than ests. All plant and animal species encountered within 1 percent of Puerto Rico's land surface remained in the Baiio de Oro are listed in tables. pristine condition (Wadsworth 1950b), and the LEF, the largest contiguous undisturbed forest on the Puerto Rican mainland, surrounded the Baiio de Oro. OVERVIEW OF MAJOR There is no evidence of previous exploration or scien- FOREST RIESEXRCH tific collections in the Baiio de Oro. Moreover, there is no evidence of logging, hunting, or diversion of water Numerous studies of the climate, flora, fauna, and resources. Scattered banana plants and the remains of ecology of the Luquillo Mountains have already been a house, however, are located near the confluence of the completed, ranking the LEF among the best studied Rio de la Mina and Rio Mameyes, suggesting that the tropical forests in the world. The citation of a few major area had been occupied at least on an interim basis for references will indicate the extent of the investigations. some time. A bibliography with nearly 2,000 entries on Puerto Rican forestry research including texts, journal and Objectives newspaper articles, theses, proceedings, and reports, most written between the early 1880's and 1978, was The purpose of this report is to compile existing compiled by the Institute of Tropical Forestry (now the knowledge of the Baiio de Oro to serve as a basis for International Institute of Tropical Forestry) library further investigations. The main effort is to call atten- staff (Mosquera and Feheley 1983). Summarizing past tion to the nature of existing literature rather than to research in the Luquillo Mountains, Wadsworth (1970) Effects of Hurricane Hugo in the BaiLo de Om Natural Area. cited 118 references on the geography, climatology, geol- whose numbers had declined rapidly during the 1960's, ogy, flora, fauna, ecology, archeology, agriculture, and was initiated in 1968 throughout the LEF (Snyder and forestry of the Luquillo Mountains. Both works also others 1987). Parrot nesting boxes were installed at two contain information on early botanical exploration of locations in the upper reaches of the Baf-10 de Oro the mountains. during the 1970's (fig. 2) as part of the research pro- From 1939 through 1963, issues of the "Caribbean gram. Parrot observations and implementation of the Forester" highlighted early Forest Service investiga- parrot recovery program continue today. tions in the mountains. Between the early 1960's and Studies conducted in the Baiio de Oro Natural Area mid-1970's, the arborescent vegetation of Puerto Rico are covered in more detail in subsequent chapters. To and the U.S. was described based on facilitate future investigations of the flora and fauna in past research and numerous field observations (Little the Bafio de Oro, a list of select references has been and others 1974, Little and Wadsworth 1964). prepared (appendix table 1). A compendium of information on forest plants, ani- mals, and the environment, before and after radiation, was summarized for the El Verde tabonuco forest THE BA&O DE OR0 NATURAL AREA located only 5 km northwest of the Baiio de Oro (Odum and Pigeon 1970). In 1983, the history of LEF research The information provided in this section pertains and opportunities for additional investigations were mainly to the Bafio de Oro. Relevant data from studies outlined (Brown and others 1983). In 1987, long-term elsewhere in the LEF, particularly with reference to ecological research dealing with the fauna, flora, and climate and vegetation, are also included. watershed dynamics was initiated in the Bisley water- sheds only 2 km northeast of the Bafio de Oro (Scatena Geology 1989). Moreover, current research activities in the LEF are summarized in the "Annual Letter" of the Interna- The geology of the Caribbean area and Puerto Rico is tional Institute of Tropical Forestry. complex and has been a source of controversy among Beginning in 1966, and extending through the authors who favored explanations based on theories in mid-1970's, the staff of the Arnold Arboretum (located vogue at the time. The summits of the Luquillo Moun- in Cambridge, Massachusetts) studied the Bafio de tains were first described as monodnocks, Oro's dwarf forest on Pico del Oeste. The results or residuals of old topography standing above a plain of appeared as 17 research papers in the "Journal of the subaerial erosion (Meyerhoff 1933). This interpretation Arnold Arboretum." Study of the Puerto Rican parrot, was questioned (Mitchell 1954) because uparching and PTEROCARPUS STAND

WATERSHED

PERMANENT PLOT (TR-I) 0 ALPINE MEADOW a TEMPORARY PLOTS 0 THRASHER NEST SITES @ PARROT RESEARCH PLOTS 0-0 UNIVERSITY OF PUERTO RICO FAUNAL SURVEY STATIONS

MINORITY RESEARCH PLOTS

Figure 2.-Location of research plots in the Bario de Om Natural Area. The plots surveyed in the University of Puerto Rico faunal study are numbered 1 through 13. faulting provided a more logical explanation for the migrated into the Atlantic (Burke 1988). A simple peak areas than erosion alone. In a summary of the model involving the rotation of a tectonic block contain- Island's geologic history (Beinroth 1969), Puerto Rico's ing Puerto Rico within the broad strike-slip boundary origin was attributed to a series of submarine volcanos of the is proposed to account for the formed during the Cretaceous Period. At the beginning Island's major tectonic features (Masson and Scanlon of the Tertiary Period, mountain building and uplift 1991). occurred, followed by weathering and erosion, which The Baiio de Oro is underlain by a complexly faulted reduced the Island to low hills. The central portion was and folded terrain composed chiefly of Cretaceous vol- then pushed upward, coastal areas sank, and limestone canic rocks, subordinate Cretaceous and/or Tertiary was deposited along the coasts. By the Miocene epoch, intrusive bodies, and minor lower Tertiary volcanic and Puerto Rico was conceived as a nearly level plain with sedimentary rocks (Seiders 1971a). The underlying meandering streams. The entire area was uplifted rocks are largely tuff, volcanic breccia, and tuffaceous again to over 1,000 m in elevation, and a new erosive sandstone and siltstone, chiefly marine (Cox and cycle was initiated. Briggs 1973). Lava probably constitutes more than 15 Recent explanations of geologic history in the Carib- percent of the 10,000 m or deeper section and is chiefly bean area rely on plate tectonics but still reflect contro- concentrated in the lower part and locally in the middle versy. North America, , and Africa part. Limestone occurs sporadically in the upper part began to diverge about 175 million years ago through a of the section. In the Bafio de Oro, five major geologic series of rifting episodes that created the Gulf of Mex- mapping units have been identified (fig. 3). Of the ico and the Caribbean Sea (Dillon and others 1987-88). stratified deposits, unnamed volcanoclastic rocks, Numerous geologic events, previously considered to be a which included marine-deposited andesitic to what is variety of independent island arc systems formed at thought to be basaltic volcanic sandstone, and fine vol- different places and times, now appear as a sequence of canic breccia with subordinate cherty mudstone, plate events reflecting a single great Caribbean Island occupy slightly more than half the area. Cherty arc system that was constructed in the Pacific and mudstone lies in a thin strip in the southeastern INTRUSIVE ROCKS

.QUARTZ DlORlTE (TQD) 240 ha (32.2 %)

DlORlTE (TD) 25 ha (3.4 '10)

STRATIFIED ROCKS

TABONUCO FORMATION (KT) 32 ha (4.3 %)

>:;ri,,.> UNNAMED VOLCANOCLASTIC ROCKS (KU) 387 ha' (51.9 '10)

MUDSTONE MEMBER (KUM) 61 ha (8.2 '10)

Figure 3. - Geologic map of the Bario de Oro Natural Area (Seiders 1971a, 1971b). portion. The tabonuco formation, composed of andesi- the south to 245 m in elevation where the Rio Marneyes tic to basaltic volcanic sandstone (about 60 percent), flows out to the north. The average gradient between mudstone (about 30 percent), and volcanic breccia and the high and low points in the watershed is 220 m/km. conglomerate (about 10 percent), lies along the north Two main ridges are evident within the Baiio de Oro. and northwestern pheriphery. The first trends northeast from Pico del Oeste to a Of the intrusive rocks, nearly one-third of the area is 685-m high point on the northeastern border of Bario composed of quartz diorite in which quartz accounts de Oro, never descending below a 490-m elevation. This for about a quarter of the mineral composition. A zone ridge separates the upper portions of the Rio Mameyes of contact metamorphism surrounds the quartz diorite, and Rio Fajardo watersheds. The Rio Fajardo flows out which exhibits metamorphosed volcanoclastic rocks the eastern border of the B&o de Oro at an elevation of typically harder and darker than unmetamorphosed 350 m. The second ridge, trending northwest from Pico equivalents. Hornblende diorite and quartz diorite are del Oeste along Route 930, descends gradually to about also found in the east central part of the Bario de Oro. 700 m at the western edge of the Baiio de Oro. More detailed descriptions of the mapping units are Nearly 71 percent of the Baiio de Oro lies between provided by Seiders (1971b). 400 and 700 m in elevation, with about 11 percent < 400 m and 18 percent > 700 m in elevation (fig. 4). The Physiography terrain is steep. About 47 percent of the 745 ha is in The Baiio de Oro measures 3.55 km from north to slopes >60 percent, with 48 percent in slopes between south and 4.15 km from east to west (fig. 4). Total relief 30 and 60 percent, and only 5 percent in slopes ~30 is 780 m, ranging from 1,025 m on Pico del Oeste on percent (fig. 5). 'PICO DEL OESTE

Figure 4.- Topographic map of the Baa de On, Natural Area.

Soils recognized were Guayabota-Ciales-Picacho association on very steep land, Los Guineos-Yunque-Stoney rock Most of the Baiio de Oro is inaccessible, and only land association on steep land, and the Utuado- limited information is available regarding soils. Picacho-Stony rock land association on very steep land. Ultisols, occupying about one-third of the 745 ha, and Subsequently, an effort was made to develop soil Inceptisols, occupying the remaining areas, are the mapping units for the LEF (fig. 6). The largest unit only major soil orders that have been identified (fig. 5). classified was the Yunque-Los Guineous Complex, In general, the Ultisols are confined to the largest river occupying nearly 40 percent of the Baiio de Oro (fig. 6). valleys below 600 m in elevation. The Inceptisols, in The next largest unit, accounting for 25 percent of the contrast, occupy the main ridges and adjacent terrain Baiio de Oro, was the Picacho-Utuado Complex. down to 300 m in elevation. Soils of Pico del Oeste's dwarf forest, designated as The Soil Conservation Service tentatively classified lithic tropaquents, have a mucklike surface 25 to 30 cm the entire area as the Los Guineos-Guayabota rock thick with organic matter up to 50 percent (Lyford land association (Boccheciamp 1977). This area is char- 1969). A distinctly mottled gray gleyed horizon lies acterized by shallow to deep, well-drained to poorly below, and this is underlain by massive, plastic, non- drained, strongly sloping to very steep soils on volcanic sticky clay with weathered rock fragments in places. uplands in tropical rain forests. The specific units The pH throughout the horizons ranges between SOILS INCEPTISOLS - 497 ha (67.7 %) ULTISOLS - 248 ha (33.3 O/O) SLOPES

0 -30°/0, 35 ha (4.70/0)

...... 31-60 O/o, 360 (48.3 Ole)

Figure 5.-Soil orders and slopes in the Baib de Oro Natural Area (Institute of %pica1 Forestry files).

4.3 and 4.9. Seepage water entered from all horizons Atlantic. The abrupt elevational gradient from the base when trenches were dug into the soil. of the mountains to the summits profoundly influences The roots of dwarf forest vegetation are found in four local climate. general habitats: the soil, immediately above the soil in Four major systems may be superimposed on the cryptogams or litter, appressed to trunks and trade wind regime influencing local weather (Odum branches, or hanging freely (Gill 1969). About 80 to 90 and others 1970): polar troughs (temperate, low pres- percent of the woody roots are just under the forest sure troughs moving southeastward); easterly waves litter or within 2 to 10 cm of the soil surface. Tree (low pressure troughs moving westward); shear lines stems are covered not only with epiphytes and roots but (remnants of cold fronts that reach tropical latitudes in also with a soillike material high in organic matter the winter); and tropical storms (low pressure centers, derived from the decomposition of epiphytic material with closed isobars and circular converging airflow, and trapped leaves. moving westward). Tropical storms, particularly if mov- ing slowly, may cause torrential rainfalls (Calvesbert Climate 1970). The Island is also located within the hurricane belt of the Caribbean and occasionally experiences the Puerto Rico, situated in the northeast trade wind high winds and heavy rains that accompany these belt about 1,800 km from the Equator, has a tropical storms. marine climate (Calvesbert 1970). The longest day No permanent climatic stations are located within (about 13.2 hours) varies only about 2 hours in length the Bafio de Oro. Climatic data are available from one from the shortest day (about 11.0 hours). The LEF, temporary station situated on Pico del Oeste and from located in the northeastern part of the Island, presents six other LEF sites located at short distances from the the first obstacle to the trade winds crossing the Bafio de Oro (table 1) (fig. 1).Station records vary with PICACHO - UTUADO COMPLEX 5 TO 40 '10 SLOPES

Figure 6.- Soil mapping units in the Bario de Om Natural Area (Huffaker [In press]).

able 1. -Mean annual climatic data for several sites in and around the Bario de Om Natural Area*

Relative Solar Site Elevation Rainfall Temperature humidity radiation

Meters Millimeters "C Percent 1 day+ Catalina* 150 2450 23.9 88 ....B Sabana 4 300 35609 21.7* 79* .... Bisley 350 3000** ...... La Minatt 715 4600 21.1 ...... Pico del Oeste* 1036 4530 18.6 98 262 Pico del Este 1050 44500% 18.70s 9891 .... El Yunque* 1065 4000 18.3 98 262

*Dates and durations of records vary by site and parameter. See figure 1 for locations of climate stations. tl = langley = 1 calorie/cm2. *Record 1958-62 (Briscoe 1966). SBlank field indicates missing data. ?Crow and Weaver 1977. **Record 1973-79 (Snyder and others 1987) and 1985-87 (Bosch, unpublished) cited by Scatena 1989. ttword 1935-43 (Wadsworth 1948). *Record 3/1/66 to 2/28/67 except relative humidity that was measured from 7 to 10166 and 12/66 to 2/67 (Baynton 1968). sPRecord 1970-82 (U.S. Department of Commerce 1970-82). q'BRecord 11/68 to 6/69 Weaver 1972b). regard to data collected, years sampled, and duration of Other informative rainfall data were summarized for measurements. They indicate trends, but comparisons the La Mina station (Brown and others 1983, Wads- among sites are tenuous. Data from most of the perma- worth 1948). Fifty days out of the year, la Mina received nent and temporary climatic stations in and around the >2.54 cm (1 inch) of rainfall. Typical rainfalls, however, Luquillo Mountains were graphed and summarized in lasted 0.5 hour, delivered 3 mm of rain, and occurred a previous report (Brown and others 1983). Salient 1,625 times per year. The maximum rainfall recorded observations from that report have been incorporated for 1 month was 1,030 mm. into the following text on climate. The total duration of rainfall events varied during Precipitation. -Much of Puerto Rico's rainfall is the year. The longest durations of rainfall occurred orographic, caused by the ascent of moisture-laden from November to January and in June, coinciding trade winds over mountain barriers (Calvesbert 1970). with periods of lower monthly rainfall. This indicates At Catalina, Sabana 4, and Bisley, between 150 and that during these months storm events are longer but 350 m in elevation, mean rainfall varies between 2,450 of lower intensity. Short durations of rainfall occurred and 3,560 mmlyr (table 1). The four remaining sites, during July through October coinciding with periods of located at 715- to 1,065-m elevations, south to west of higher rainfall and indicating greater intensity of the Baiio de Oro, average 24,000 mm/yr. storms. The total duration of rainy weather during the Rainfall fluctuates considerably from year to year year was about 22 days, or proportionately about 6 (Wadsworth 1948, 1970). At the La Mina station, the percent of the year. About 55 percent of this rain 9-yr mean of 4,600 mmlyr was exceeded twice by more occurred between 6 a.m. and 6 p.m. than 37 percent, and during 1 year, it was 20 percent Hail is a relatively rare event in Puerto Rico, below the mean. Similar fluctuations in annual rainfall although incomplete records and personal accounts were evident from coefficients of variation between 15 indicate that it has fallen at some time virtually every- and 38 percent for other climatic stations in and adja- where (Calvesbert 1970). During February 1969, a hail- cent to the Luquillo Mountains (Brown and others storm lasting about 15 minutes occurred on Pico del 1983). Este (author, personal observation). The hailstones Rainfall also varies during the year (fig. 7). At Pico were relatively small, averaging about 0.5 cm in size. del Este and La Mina, February, March, and April are Zkmperature. - Mean temperatures in Puerto Rico drier than the remaining months. The wettest months characteristically have little variation between the for Pico del Este are May, October, and November; the warmest and coolest months, and between years (Cal- wettest months for la Mina are May and November. vesbert 1970). Mean annual temperature decreases The drier months of February and March and the from 22 to 18 "C with ascent from 300 to 1,065 m in wetter month of May also characterize other climatic elevation in the Luquillo Mountains (table 1). At stations in and around the Luquillo Forest (Brown and Sabana 4, the mean annual temperature varies from 21 others 1983). The highest recorded daily rainfall for the "C between December and March to 24 OC in August LEF, 485 mm, was observed during May on Pico del and September (Briscoe 1966). Mean annual tempera- Este (Weaver 1972a). tures on El Yunque and Pico del Este vary from 17 or

PIC0 DEL ESTE LA MlNA CATALINA 4,450 rnm/yr 4,600 rnmlyr 2,450 rnmlyr

18.7 OC 21.1 OC 23.9 OC 1,050 m 715 rn 150 m

Or: O C O C

111110 0-0 OJFMAM JJASOND JFMAMJJASOND MONTH MONTH MONTH

Figure 7.- Climatic diagrams for Pico &l Este (U.S. Department of Commerce 1970-82), La Mina (Wadsworth 1948), and Catalina (Briscoe 1966). Mottled areas indicate rainfall >I00 mmlmonth, and striped areas indicate a water surplus. 18 "C between December and March to 19 or 20 "C velocity from 14 to 18 km/hr were recorded at El Yun- between August and October (Briscoe 1966, U.S. que in December, January, April, and September. At Department of Commerce 1970-82). Diurnal tempera- Catalina, peaks from 4 to 6 kmhr were observed in ture variation and temperature range in any given April and from July through September. month are larger at lower elevations than at higher Diurnal variation in wind velocity showed interest- elevations (Brown and others 1983). ing contrasts. On El Yunque, depending on the month, On Pico del Oeste, the highest and lowest recorded maximum velocities from 14 to 16 kmhr occurred from temperatures in 1966-67 were 26 and 13 "C (Baynton 4 a.m. to 10 a.m., with minimum velocities between 11 1968). These temperatures corroborate observations on and 14 kmkr from 12 noon to 4 p.m. (Briscoe 1966, Pico del Este (author, personal observation). One might Brown and others 1983). At Catalina, maximum wind speculate that the maximum range of temperatures velocities from 4 to 6 km/hr occurred between 10 a.m. experienced in the B&o de Oro lies between 10 "C at and 4 p.m. and minimum wind velocities from 2 to 3 the summits and slightly more than 30 "C at the lowest kmlhr at other hours. elevation. Freezing temperatures are unknown any- Cloud Cover and Solar Insolation. -Cloud cover where in Puerto Rico (Calvesbert 1970). increases with elevation in the Luquillo Mountains Relative Humidity. -The dewpoint temperature where the summits are frequently enveloped in clouds varies little over Puerto Rico, indicating that the over- when the surrounding lowlands are clear. February lying air mass is fairly constant with regard to mois- and March are the months when the peaks are most ture content during the year (Calvesbert 1970). For likely to be cloud free. On Pico del Oeste, contrasting summit locations in the LEF, the mean annual relative conditions were observed during 1 year of measure- humidity is >98 percent (table 1).Mean monthly rela- ment. Two notable periods, one of 16 days in June 1966 tive humidity at El Yunque is near 100 percent for all and the other of 15 days in January 1967, were recorded months except February, when it decreases to about 90 during which cIoud cover enveloped the peak continu- percent. At lower elevations, Catalina and Sabana 4, ously (Baynton 1968). During November 1966, however, the mean annual relative humidity varies between 79 a 3-week period averaging 15 hours per day of cloud- and 88 percent. Individual mean monthly values range free weather was observed. between 76 and 92 percent, with lows in March and Pico del Este was one of 10 North American sites highs in September through November (Brown and where cloud water was considered an important input others 1983). to local ecosystems (Weathers and others 1988). The diurnal variation in relative humidity at El Yun- Between May 1984 and November 1985, cloud water que is slight in comparison to that of the Catalina and and rainfall samples were collected on an event basis Sabana 4 locations. At El Yunque, it is at or near 100 and chemically analyzed for concentrations of Ca2+, percent during the evening hours (from 6 p.m. to 8 Mgz+, K+, Na+ , ammonium, sulfate, nitrate, and a.m.). The low is at 1 p.m., when it averages about 95 C1-. The pH was determined, and at a few sites, trace percent. At Catalina and gabana 4, the relative humid- metals (Pb, Cu, and Zn) and organic compounds were ity is near 95 percent during the evening hours. During sampled. daylight hours, it decreases to 75 percent at Catalina The sea salt component, variable between events, and 70 percent at Sabana 4, at 2 p.m. and 1 p.m., contributed to a high mean ionic strength of samples respectively. from Pico del Este Weathers and others 1988). The Wind Velocity and Direction. -The steadiness of variability was related to wind velocity and its influ- the trade winds, blowing mostly from an easterly direc- ence on aerosol production. Comparably high nitrate tion, is the outstanding feature of wind in Puerto Rico concentrations were attributed to the oxidation of (Calvesbert 1970). On El Yunque, the prevailing mean reduced nitrogen gases from the rain forest or from monthly wind direction is from the northeast. In Janu- local pollution. Ammonium concentrations, also consid- ary and September, however, winds are from the south, ered high, may have been associated with the rapid and in December, from the east. In contrast, at the decomposition of organic matter from the surrounding base of the mountains in Catalina, winds are more rain forest. One cloud sample was visibly contaminated variable, blowing from the south in January, from the with a reddish material, possibly dust from the Sahara east-northeast in February and March, from the east Desert. More recent work assessed the influence of sea from April through August, from the south in Septem- salt aerosols on precipitation chemistry at El Verde, ber, and from the northeast from October through located in the LEF's tabonuco forest (McDowell and December. The trade winds, particularly closer to the others 1990). coast, are modified by land and sea breezes (Calvesbert Cloud cover affects incoming solar radiation. Mean 1970). annual solar radiation on El Yunque and Pico del Oeste Mean monthly wind velocity ranged from 8 to 18 averages 262 langleyslday, or 60 percent of that km/hr at El Yunque and from 2 to 6 kmhr at Catalina received at sea level on the northeastern coast of (Briscoe 1966, Brown and others 1983). Peaks in wind Puerto Rico (Baynton 1968, Briscoe 1966). Because the I A STORM I TYPE B STORM I TYPE C STORM

1 1 I I I I I 1 I I I 0 10 20 30 40 50 60 70 80 90 99 YEAR

Figure 8.-Hurricane record for Puerto Rico from 1700 to 1970 (Salivia 1972) updated to 1992: type A storm, vortex of hurricanepassed directly over the Island with hurricane force winds; type B storm, vortex of hurricane may or may not have passed over the Islnnd, but only part of the Island experienced hurricane force winds; type C storm, vortex passed at some distance from the Island, which experienced high winds (not hurricane force) and heavy rains; double I bar, two storms in the same year with intensity of second storm indicated by position of second I bar within the first; horizontal line from 1943 to 1992, years of measurement of tree growth in the Lquillo Forest; black circle, type A storms that passed directly over the Luquillo Forest. spectral composition of light changes little with cloudi- Luquillo Mountains (fig. 8, 9). Based on existing data, ness, light energy available for photosynthesis on the hurricanes may be expected to pass directly over the Luquillo Mountain summits is also reduced to 60 per- LEF once every 62 years and to pass within 60 km once cent of that received in coastal areas (Baynton 1968). every 22 years (Scatena 1989). The LEF, then, could The mean monthly totals of incoming solar radiation expect some damage from type A hurricanes at least for the coast and summits parallel each other. At the once every 20 to 30 years. summits, mean monthly solar insolation peaks between The effects of Hurricane San Felipe of 1928, as 320 and 380 langleyslday during March and April and reported for the Luquillo district, included defoliation is lowest at 175 langleyslday during December. Diurnal and breakage of branches, later followed by an abnor- insolation patterns are also similar and peak near 1 mal production of seeds (Bates 1929). Hurricane San p.m. (Briscoe 1966, Brown and others 1983). Cipriano of 1932 passed directly over the LEF and Radiation fog may occur during the early morning must have done considerable damage to the forest hours in interior valleys throughout Puerto Rico, based on compositional and structural changes including those of the LEF. Often seen as blankets of observed during recovery (Crow 1980; Weaver 1986a, cloud cover concentrated in low areas, these rapidly 1989). Hurricane Santa Clara of 1956 had very little dissipate as the day progresses. effect on the LEF (Wadsworth and Englerth 1959). Hurricanes. - September is the month of most fre- Hurricane Hugo of 1989, the first to have a major quent hurricane occurrence followed by August and impact on the Luquillo Forest since San Cipriano of July (Salivia 1972). About 80 storms have occurred in 1932, passed over the northeastern tip of Puerto Rico. Puerto Rico since the early 1700's (fig. 8), many of Sustained winds were in excess of 225 kmthr, and the which probably caused localized damage to vegetation total 3-day rainfall ranged up to 34 cm (Larsen 1989, in the Luquillo Mountains. Of these, 15 were A storms Matos 1989). More than 200 landslides were detected (vortex of the hurricane passed directly over the Island within the mountains of northeastern Puerto Rico with hurricane-force winds), and 12 were B storms (Larsen 1989). Defoliation, stripping of branches, and (vortex of the hurricane may or may not have passed tree fall were evident throughout the Baiio de Oro, over the Island, but only part of the Island experienced which was well exposed to the storm. Hurricanes are of hurricane-force winds), for an average of one storm biological interest because of the long-term effects they over at least part of the Island every 12 years (fig. 9). Of have on forests and wildlife (Crow 1980; Walker and the A storms, four had trajectories directly over the others 1991; Weaver 1986a, 1989). Figure 9.-Path of type A hurricanes with trajectories directly over Puerto RRico from 1700 to 1970. Solid lines are known trajectories and dashed lines are assumed trajectories based on descriptions (adapted from Saliuia 1972). Hurricane Hugo of 1989 passed just east of Fajardo.

Hydrology were recorded. Minimum discharge, 0.86 m3/s, occurred on May 3,1984. Records are rated as fair with Two major rivers, the Rio Mameyes and the Rio low flow affected by diversions for water supply. Fajardo, have their headwaters in the Baiio de Oro Flooding is most likely to occur between May and (figs. 2 and 4). The Rio Mameyes, made up of three November, the time of maximum rainfall expectancy. tributaries with a combined river length of about 12 The combination of heavy rainfalls and steep slopes km, flows north draining two-thirds of the Baiio de sometimes concentrates runoff into flows that exceed Oro. The Rio Fajardo, with one tributary, has a com- stream channels for short periods. Flooding is most bined river length of 7 km. It flows north and then likely to be associated with major rain-producing east, draining the remainder of the Baiio de Oro. events such as tropical storms, cold fronts, or hur- A gauging station (I.D. No. 655) is situated at an ricanes (Calvesbert 1970). Flooding in the upper head- 84-m elevation on the Rio Mameyes at the border of the waters of the Rio Mameyes and Rio Fajardo, however, is LEF (fig. 1). Records span periods from August 1967 to localized and of short duration because of the steep December 1973 and from June 1983 to the present topography. (Curtis and others 1989). A 6-year record of annual discharge for the station ranged between 200 and 500 cm, with a mean and standard error of 300 + 44 cm. FLORA The mean discharge of total dissolved solids associated with this flow was 3,324 t/yr and was linearly related to Major Forest 'Qpes river discharge (Brown and others 1983). The mean rates of monthly discharge are the lowest and with the least variability between February and April (fig. 10). Three sets of nomenclature are commonly used to They peak in May and October, with the greatest vari- refer to the forests of the LEF, and each serves a ability in October. Water quality parameters are shown particular audience: local names in Puerto Rico in table 2. (Wadsworth 1951), Beard's (1944,1949) terminology in A second gauging station, situated at a 42-m eleva- the Caribbean, particularly the Lesser Antilles, and tion on the Rio Fajardo, has experienced flood damage Holdridge's (1967) life zone system commonly used in on several occasions. Low and peak flow discharges Central and South America and the Greater Antilles. were sometimes recorded in 1960-61; water discharge, The Baiio de Oro is divided into two life zones (Ewe1 however, has been recorded from March 1961 to the and Whitmore 1973): the subtropical rain forest and present (Curtis and others 1989). The average dis- the subtropical lower montane rain forest (fig. 11). In charge over the 28-year period is 1.98 m3Is. The max- Puerto Rico, these life zones are confined to the imum discharge for the same period occurred during Luquillo Mountains. The subtropical rain forest is Hurricane Hugo, September 18, 1989, when 665 m3/s located at intermediate elevations to the windward Table 2.-Mean water qualityparameters for the Rio Mameyes for the The origin of the meadow is uncertain but may be period 1969-74 * related to site disturbance such as a landslide during Values* heavy rains or a major hurricane (Guariguata 1990, Parameter (mean -t SE) Larsen 19891, followed by soil changes Weaver 1990). Once formed, the hardpan prevents percolation and Temperature ("C) 22.9 (0.2) Specific conductance (p)* 85.3 (17.1) may retard the penetration of tree roots. PH 7.2 (0.10) A Pterocarpus stand extends behind the eastern Alkalinity fmg1L)S 32.8 (2.7) bank of the Rio Mameyes at the confluence of the Rio Ca (mglL) 10.5 (0.4) de la Mina (fig. 2). The stand, occupying c 1ha, borders Mg fmg/L) 2.5 (0.03) the Bafio de Oro. Its location at a 245-m elwation in the Na (mglL) 6.7 (0.2) K ((mglL) 0.60 (0.04) LEF is notable because most Ptemcarpus forests in the cl (mg/L) 8.4 (0.2) Caribbean are situated in intermittently flooded SO, (mglL) 4.0 (0.4) coastal lowlands. NO8 (mg/L) 0.20 (0.05) The stand was studied in detail as part of a thesis Dissolved PO, (mglL) 0.30 (0.3) program (Alvarez-Lopez 1990, Alvarez Ruiz 1982). Sev- *Brown and others 1983, based on U.S. Geological Survey records. eral of the larger trees range from 40 to 80 cm in tSE = standard errors (in parentheses); number of observations diameter, and the tallest is 32 m. Seedling regeneration = 34; elwation = 84 m. is abundant. Detailed structural information is avail- tPs = microsiemens per centimeter at 25 "C (measure of water's able for the stand, including species importance values, capacity to conduct a current). a species-area curve, a complexity index, a stand pro- PmgiL = milligrams per liter. file, phenological observations, root biomass, soil pro- file, litter standing crop, and soil organic matter storage. where it occupies 1,420 ha, or 13 percent of the LEF. Twenty-seven percent of the 1,420-ha total, or 385 ha, is in the Baiio de Oro. The second life zone is concen- 'bee Species Distribution trated on windward slopes and summits and occupies 1,180 ha, or about 10 percent of the LEF. Thirty per- The LEF has 225 species of native trees in 144 gen- cent of the 1,180-ha total, or 360 ha, is in the Baiio de era and 59 plant families. The closest botanical Oro. affinities are with Hispaniola and , but South Four of Beard's forest types are recognized in the America appears to have been the source of the first Bafio de Oro: lower montane rain forest, montane rain immigrants (Little 1970). Forty-one percent of the forest, palm brake, and dwarf forest. Locally, these LEF's tree species are also found on the mainlands of forests are known as tabonuco, colorado, palm, and South America, , , and Florida. dwarf forests, respectively. For convenience, local Moreover, 28 percent are found in the but not on the continents, and 31 percent are endemic to names will be used hereafter in the text. General descriptive information for the four forest Puerto Rico (Little and Woodbury 1976). Of the 88 species classified as endemic or rare in the types is provided in table 3. The tabonuco forest, extending to about a 600-m elevation in the LEF, LEF, 23 species are endemic only to the LEF, another occupies 56 percent of the Baiio de Oro (fig. 11). It is 45 species are endemic to Puerto Rico and found in the LEF, and 20 species are classified as rare in Puerto dominated by Dacryodes excelsa, Sloanea berteriana, and Manilkara bidentata in the overstory. The colorado Rico but also native to areas outside of Puerto Rico. forest, which lies between 600 and 900 m in elevation, is dominated by Cyrilla racemiflora, Pico del Oeste Flora chrysophylloides, and M. garciniaefolia in the over- story. The dwarf forest, a gnarled, epiphyte-laden, and Between 1966 and 1977, staff members of the Arnold dense forest type, occupies the slopes and summits Arboretum and collaborators published the results of above 900 m in elevation. Tabebuia rigida, 17 studies conducted in the dwarf forest of Pico del spaihulata, and Eugenia borinquensis are the most Oeste. An introduction, objectives, and general descrip- common species. Finally, the palm forest, dominated by tion of the dwarf forest program were outlined by Prestoea montana, the sierra palm, is concentrated on Howard (1968, 1970b). The work encompassed studies steep slopes and in ravines above a 500-m elevation. of species composition (vascular plants, mosses, leafy Hepaticae, and algae), which are reported below. Vascular Plants. -A survey of the vegetation for Other Vegetation Mes the entire Pico del Oeste summit area disclosed 97 There is an alpine meadow in the dwarf forest of the species of vascular plants, 85 of which were considered Baiio de Oro (fig. 2). Its soil is characterized by a to be the principal species (table 4). Of the latter, 31 hardpan 60 to 70 cm below the surface (Odum 1970). were species of ferns, 14 were Monocotyledoneae, and 140 - RIO MAMEYES ELEVATION = 83.8 m 120 -

100 - -,- -5 - T L - 2 80 fk 60 - 5 - rt! - B 40 - I, 20 - -L - & i

MONTH

Figure lo. - Mean monthly discharge fmm thRio Mamqes (in black circles) and range of monthly discharges (bars) (Brown and others 1983).

DWARF FOREST a50 ho 16.7

Figure 11.- Life zone and forest type map of the Baa di Om Naiuml Area (Institute of ~icalForestry files). Table 3. -Forests of the Bario de Om Natural Area

Forest Tree Elevation type Area Tree species* height Hectares Percent Total No.lha ------Meters ------Tabonuco 416 56 153 50 > 30 ~600 Colorado 136 18 101 35-40 15 600-900 Palm 143 19 26 < 20 15 >500 (steep slopes and arroyos) Dwarf 50 7 43 < 15 5-7 > 900 (exposed slopes - - - and summits) Total 745 100 225 -- - *Little and Woodbury 1976. Species data refer to entire LEF and are not additive because of overlap among forest types. The number of species in the natural area is unknown.

Table 4. - species list for Pico del Oeste in the Bario de Om Natural Area * Nomenclature

Lycopodiophyta

Lycopdiaceae Lycopodium cernunm L. L. taxifolium Sw.

Selaginellaceae Selaginella krugii Hieron S. substipitata Spring

Polypodiophyta

Cyatheaceae Cyathea borinquena (Maxon) Domin C. pubescens Mett. ex Kuhn Lophosoria quadripinnata (Gmel.) C. Chr.

Pol ypodiaceae Blechnum divergens (Kunze) Mett B. lineatum (Sw.) Hieron B. underwoodianum (Broadh.) C. Chr. Cochlidium minus (Jenm.) Maxon C. seminudum Willd.) Maxon Diplazium centripetale (Baker) Maxon D. grandifolium Sw. D. 1 'herminieri Hieron D. striatum (L.) Presl Elaphoglossum firmum (Mett.) Urban G. hessii (Maxon) Alain G. serrulata (Sw.) Sw. G. taenifolia (Jenm.) Proctor Lindsaea stricta (Sw.) Dryand Oleandra articulata (Sw.) Presl Peltapteris peltata (Sw.) Morton Pdybotrya cervina (L.) Kaulf Polypodium chmdes Spreng I? loriceum L. Thelypteris decussata (L.) Proctor

Hymenophyllaceae Hymenophyllum linceare Sw. H. macrothecum Fee Zkichomanes crispurn L. T. rigzdum Sw. Table 4. -Vascular plant species list for Pico del Oeste in the Bario de 0x1Natural Area*- Continued Nomenclature

Magnoliophyta-Liliatae

Gramineae Andropogon bicornis L. Arthrostylidium sarmentosum Pilger Ichnanthus pallens (Sw.) Munro Isachne angustifolia Nash

Cyperaceae Cawpolystachya Sw. ex Wahlenb Eleocharis yunquesis Britton Fimbristylis dichtoma (L.) Vahl Scleria secans (L.) Urban

Palmae Prestoea mntana (R. Grah.) Nichols

Araceae Anthurium dominicense Schott

Bromeliaceae Guzmania berteroniana (R. & S.) Mez Vriesia sintenisii (Baker) Smith & Pittend

Dioscoreaceae Rajania cordata L.

Zingiberaceae Renealmia antillarum (R. & S.) Gagnep

Orchidaceae Brachionidium parvum Cogn Dilomilis mntana (Sw.) Summerhayes Epidendrum nocturnum Jacq E. pallidiflorum Hook

Piperaceae Pepemia emarginella (Sw.) DC . i? hrnandiifoliu Wahl) A. Dietr

Chloranthaceae Hedyosmum arborescens SW.

Moraceae Cecropia peltata L.

Urticacea Pilea krugii Urban R obtusota Liebm R yunquensis (Urb.) Britt. & Wds.

Lauraceae Ocotea spathulata Mez

Magnoliaceae Magnolia splendens Urban

Cunoniaceae Weinrnannia pinnata L. Table 4. -Vascular plant species list for Pico del Oeste in the Baiin de Om Natural Area * - Continued -- Nomenclature

Meliaceae Dichilia pallida Sw.

Aquifoliaceae Zlex sintenisii (Urb.) Britton

Celastraceae 'Ibrralbasia cuneifolia (C. Wr. ex Griseb.) Krug & Urban ex Segui

Ochnaceae Sauvagesia erecta L.

Marcgraviaceae Marcgrauia sintenisii Urban

Theaceae Cleyera albopunctata (Griseb.) Krug & Urban

Guttiferae Clusia grisebachiana (Planchon & Triana) Alain C. gundlachii Stahl

Begoniaceae Begonia decandra Pav. ex A. DC.

T hymelaeaceae Daphnopsis philippiana Krug & Urban

MY- Calyptranthes krugii Kiaersk. Eugenia borinquensis Britton

Calycogoniurn squarnulosurn Cogn Mecranium arnygdalinum (Desr.) C. Wright ex Sauv Miconia fowoloto Cogn M. pachyphylla Cogn M. pycnoneum Urban M. sintenisii Cogn

Ericaceae Gonocalyx portoricensis (Urb.) A. C. Sm. Hornemannia mcemosa Vahl.

Myrsinaceae Ardisia luquillensis (Britton)Alain Gmmmadenia sintenisii (Urb.) Mez Wallenia yunqmnsis (Urb.) Mez

Sapotaceae Micropholis garciniaefolia Pierre.

Symplocaceae Symplocos rnicrantha Krug & Urban

Oleaceae Haenianthus salicifolius Griseb. var. obovatus (Krug & Urb.) Knob1

Convolvulacear! Ipomoea repanda Jacq. Table 4.- Vascular plant species list for Pico del Oesle in the Barw de Om Natuml Area* - Continued Nomenclature

Boraginaceae borinquesis Urban

Bignoniaceae 'Ihbebuia rigida Urban

Alloplectus ambiguus Urban C;esneria sintenisii Urban

Acanthaceae Justicia martinsoniana Howard

Rubiaceae Hillia parasitica Jacq. Psyclwtria berteriana DC. P. guadalupensis (DC.) Howard Roncleletia portoricensis Krug & Urban

Campanulaceae Lobelia portoricensis Wke) Urban

Compositae Clibadium emsum (Sw.) DC. Mikania pachyphylla Urban

*Source: Howard 1968.

40 were Dicotyledoneae (Howard 1968). Of the species dominated synusia was observed, a phenomenon appar- sampled on Pico del Oeste, 32 percent were endemic to ently related to an increase in height and changes in Puerto Rico, 40 percent were restricted to the Greater host material. Moreover, a vertical shift of algae, or and Lesser Antilles, and 28 percent were found in the season4 response to environmental utilization, is evi- Antilles and in continental areas (Howard 1968). dent during the year, probably as a reaction to greater Mosses. - Twenty-three species of mosses were iden- cloud cover during the wet season than in the dry tified (table 5) (Russell and Miller 1977). Most species season. grow at the base of trees with about half occurring at Other studies of the flora on Pico del Oeste included other levels. Species growing on the forest floor have a the following topics: stem growth, form, and leaf struc- lower resistance to desiccation than those in treetops, ture (Howard 1969); chromosome numbers and flower- whereas the latter are more tolerant of higher light ing cycles of dwarf forest species (Nevling 1969, 1971); intensities. transpiration rates and leaf temperatures (Gates 1969); Leafy Hepatieae. -Although the dwarf forest is soil and roots, including aerial roots (Gill 1969, Lyford sometimes called "mossy," leafy Hepaticae comprise 1969); phytochemical screening and chemistry of col- most of the bryophyte flora. Fifteen families, 34 gen- ored leaves (Persinos and others 1970, Wagner and era, and 62 species were identified on Pico del Oeste others 1969); and the occurrence and growth of Marc- (table 6) (Fulford and others 1970, 1971). Considerable gravia (Howard 1970a) and Gonocalyx (Nevling 1970). differences in species composition were observed for Other Dwarf Forest Studies. -The dwarf forest hepatic flora on different peaks within the LEF. on Pico del Este, at virtually the same elevation and <2 Algae. -Some 123 species of epiphytic algae were km distant from Pico del Oeste, has also been studied identified with their vascular hosts on Pico del Oeste (Weaver 1972a, 1972b). Twenty-eight species of endemic (table 7) (Foerster 1971). Sampling disclosed that they plants and 28 species of vertebrate fauna were identi- were not uniformly distributed but were segregated fied. The arborescent vegetation contained only a few into various intergrading synusia. A general shift from tree species characterized as small in stature and high Bacillariophyta- to Cyanophyta- to Chlorophyta- in stem density and basal area. Table 5.-Moss species list for Pico del Oeste in the Barin de Om Natural Area* Nomenclature Acroporium acestrostegium A. pungens Callicostella depressa Campylopus cygneus Hemiragis aurea Hookeriopsis acicularis H. obsoletinervis Hypnelln filiformis Zsodrepanium lentulum Lepyrodontopsis trichophylla Leucobryum crispum L. rnartianum Leucoloma serrulatum L. shwaneckeanum Leucophanes calymperatum Macromitrium perichaetiale M. schwaneckeanum M. scoparium Pilotrichurn evanescens Syrrhopodon prolifer Thuidium urceolatum Dichosteleum sentosum Vesicularia sp. *Source: Russell and Miller 1977.

Cyrilla racimiflora regeneration on an overturned tree after Hurricane Hugo within the Bafio de OmNatural Area. Table 6.- Leafy Hepaticae species list for Pico dd Oeste in the Barw de Om Natural Area* Nomenclature Trichocoleaceae Dichocolea breuifissa Steph. T.elliottii Steph. T. filicaulis Steph. T. flaccida (Spr.) Jack & Steph. Isotachidaceae Neesioscyphus bicuspidatus (Steph.) Grolle Herbertaceae Herberta divergens (Steph.) Herz. H. elliottii Spr. H. juniperoidea (Sw.) Grolle H. pensilis (T. Tayl.) Spr. Bazzania bidens (Nees) Trevis. B. breuteliana (Lindenb. & Gott.) Trevis. B. cubensis (Gott.) Pagh B. eggersiana (Steph.) Pa@ B. gracilis (Hampe & Gott.) Steph. B. hookeri (Lindenb.) Trevis. B. longa (Nees)Trevis. B. longistipula (Lindenb.) Trevis B. roraimensis (Steph.) Fulf. B. schwaneckiana (Hampe & Gott) Trevis. B. stolonifem (Sw.) Trevis. Lepidozia patens Lindenb. Microlepidozia capillaris (Sw.) Fulf. Micropterygium carinatum (Grev.) Reim. M. aa2atum Steph. Telaranea sejuncta (Angstr.) S. Arnell Calypogeiaceae Calypogeia caespitosa (Spr.) Steph. C. cellulosa (Spreng.) Steph. C. crenulata Bischl. C. cyclostipa (Spr.) Steph. C. elliottii Steph. C. laxa Gott. & Lindenb. C. lophocoleoides Steph. C. peruviana Nees & Mont. Cephaloziaceae Cephalozia caribbeania Fulf. C. cmsifolia (Lindenb. & Gott.) FuK C. subfor/kda Herz. Nowellia caribbeania Fulf. N. dominicensis Steph. Odontoschismaceae Alobiellopsis dominicensis (Spr.) W. Odontoschisma denwZntum (Nees)Durn. 0.longiflorum (T.?Byl.) Steph. 0.prostratum (Sw.) Trevis. Re@caulaceae Arachniopsis coactilis Spr. Zoopsidaceae Zoopsis antillana Steph. Alobiellaceae Alobiella husmti (Gott.) Schiffn. Paracromastigaceae Leucosarmntum portoricense Fulf. Table 6.-Leafy Hepaticae species list for Pico &l Oeste in the Barb de Om Natural Area * - Continued Nomenclature

Lophocoleaceae Hetemscyphus elliottii (Steph.) Pagh Leptoscyphus gibbosus (T. Tayl.) Mitt. Lophocolea guudeloupensis Steph. L. martiana Nees

Lophcziaceae Syzygiella perfoliata (Sw.) Spr. S. rubricalis (Nees) Steph.

Jungermanniaceae Jungermannia dominicensis Spr.

Adelanthaceae Adelanthus decipiens (Hook.) Mitt.

Plagiochillaceae PlagLochila abrupta Lehm. & Lindenb. I? adiantoides (Sw.) Dum. l? amoena Steph. l? arcuota Lindenb. l? bicornis Hampe & Gott. l? bidens Gott. I! b~utdianaLindenb. l? bursata (Desv.) Lindenb. l? chinantlam Gott. l? confundens Lindenb. & Gott. l? distinctifolia Lindenb. I? divaricata Lindenb. I? dominicensis T. nyl. l? jarnaicensis Lindenb. & Hampe l? rutilans Lindenb. l? simpler (Sw.) Dum. l? subbidentata T. nyl. l? tamariscina Steph. l? ? tenuis Lindenb. scraps

Scapaniaceae Scapania portoricensis Hampe & Gott.

Radkae Radula fendleri Gott. R. inflexa Gott. ex Steph. R. kegdii Gott. ex Steph. R. longifolia Steph. R. saccatiloba Steph. spp.

F'rullaniaceae Frullania atrota (Sw.) Dum. l? bmsiliensis Raddi F. exilis T. %yl. l? kunzei Lehm. & Lindenb. I? subtilissima (Nees & Mont) Lindenb.

Lejeuneaceae Arwplolejeunea conferta (Meissn.) Evans Archikjeunea viridissimu (Lindenb.) Steph. Ceratolejeunea brevinervis (Spr.) Evans C. cornuta (Lindenb.) Steph. C. cubensis (Mont.) Schiffn. C. Frgelliformis (Steph.) Fulf. C. maritimu (Spr.) Steph. C. patentissima (Hampe & Gott.) Evans C. rubiginosa Steph. Table 6.- Leafy Hepaticae species list for Pico del Oeste in the Bario de Om Natural Area * - Continued Nomenclature -- - C. spinosa (Gott.) Steph. C. valida Evans scraps Cheilolejeunea a'ecidua Spr. C. polyantha Evans Colura clauigera (Gott. ex Schiffn.)Jovet-kt C. rhynchophora Jovet-Ast Crossotolejeuneabermudiana Evans C. boryana (Mont.) Steph. Cyclokjeunea wcedens (Gott.) Evans C. angulistipa (Steph.) Evans C. chitonia (T. Tayl.) Evans C. convexistipa (Lehm. & Lindenb.) Evans Cyrtokjeunea holostipa (Spr.) Evans Cystolejeunea lineata (Lehm. & Lindenb.) Evans Diplasiolejeunea brachyclada Evans D. pellucida (Meissn.) Schiffn. D. unidentata (Lehm & Lindenb.) Schiffn. Drepanolejeunea anoplantha (Spr.) Steph. D. crucianella (T. Thy].)Evans D. evansii Bischl. D. fragilis Bischl. D. inchoata (Meissn.) Schiffn. D. lichenicola (Spr.) Steph. scraps Euosmolejeunea clausa (Nees & Mont.) Evans E. rigidula (Nees & Mont.) Steph. E. trifaria (Nees)Schiffn. Harpakjeunea heterndonfa Evans H. subacuta Evans H. uncinata Steph. Hygrokjeunea sp. Lejeunea flava (Sw.) Nees Leptolejeunea elliptica (Lehm. & Lindenb.) Schiffn. L. hamulata Schifln. Leucolejeunea xanthocarpa (Lehm. & Lindenb.) Evans Lopholejeunea howei Evans L. miilkrianu (Gott.) Schiffn. L. sagraeana (Mont.) Schiffn. Macrolejeunea subsimpla (Nees & Mont.) Schiffn. Marchesinia brachiata Schiffn. Microlejeunea acutifolia Steph. M. bullata (T. Wl.) Steph. M. laetevirens (Nees & Mont.) Evans M. monoica Bischl. Neurokjeunea breutelii (Gott.) Evans Odontokjeunea lunulata (Web. ) Schiffn. Omphalanthus filiformis (Sw.) Nees Prionokjeunea aemula (Gott.) Evans P. aequitala Evans I? ouurriculata Evans R helkri Evana I? innovata Evans scraps Ptychocoleuspolycapus (Nees)!Crevis. Pycnolejeunea schwaneckii (Steph.) Schif'fn. Rectolejeunea bertemnu (Gott.) Evans R. phyllobola (Nees & Mont.) Evans Stictolejeunea squamata (Vir111d.) Steph. Strepsilejeunea iruroluta Steph. Symbiezidium barbiflorum (Lindenb. & Gott.) Evans S. laceratum Evans. S. transversak (Sw.) 1Crevis. kilejeunea obtusangulata (Spr.)Evans. T. sulphurea (Lehm. & Lindenb.) Steph. Thehylejeunea inflax Steph. *Sources: F'ulford and others 1970, 1971. Table 7. -Algae species list for Pico del Oeste in the Bark de Oro Natural Area* Nomenclature Cyanophyta

Chroococales Aphamcapsa biformis A. Br. A. grevillei (Hass.) Rabenh. A. roeseana DeBary Aphanothece clathrata W. & G. West A. microscopica Niig. A. sazicola Niig. Chroococcus dispersus (Keissler) Lemm. C. dispersus var. minor G. M. Sm. C. giganteus W. West C. limneticus Lemm. C. minor (Kiitz.) Niig. C. minutus (Kiitz.) Niig. 6.pallidus Niig. C. turgidus (Kutz.) Niig. C. varius A. Br. Dactylococcopsis fascicularis Lemm. D. smithii R. & I?. Chodat Gloeocapsa ~ruginosa(Carm.) Kiitz. G. polydermatica Kiitz. Gloeothece linearis var. composita G. M. Sm. G. paka (Kutz.) NZLg. G. paka (Kutz.) Rabenh. Merismpedia aeruginea B&b. ex Kutz. M. elagans A. Br. ex Kutz. M. glauca (Ehrenb.) Niig. M. punctda Meyen M. tenuissima Lemm. Microcystis aeruginosa Kiitz. M. elabens (Breb) Kutz. M. incerta Lemm. M. ramsa Braradw. M. orissica (?) W. West. Pelogloea bacillifera Lauterborn Rhabdoderma sp. Synechococcus aeruginosus Niig.

Chamaesiphonales Chamaesiphon confervicola A. Br. C. rostaffinskii Hansg.

Nostocales Anabaenu ammala Fritsch A. circinalis Rabenh. A. laze (Rabenh.) A. Br. Anabaena sp. A. owFritsch A. oscillarioides Bory ex Born. & Flah. Aulosira fritschii Bharadw. A. prolifica (?) Bharadw. A. prolifica Bharadw. Calothrir epiphytica W. & G. West C. weberi Schmidle Coelosphuerium dubium Gmn. Cylindrospermum cdenatum (?) Ralfs Gloeotrichia echinnulata (J. E. Sm.) Richter G. longiarticulnta G. S. West Lyngbya limnetica Lemm. Microchuete uberrima Carter Nostoc muscorum C. Ag. Oscillatoria agardhii Gom. 0. annae van Goor 0. foreaui Wmy Table 7.-Algae species list for Pico del Oeste in the Bario de Om Natural Area* Nomenclature 0. geitleriana Elenkin 0. limnetica Lemm. sp. Oscillatoria sp. 0.subbreuis Schmidle Phormidium tenue (Menegh.) Gom. Pseuclanabaena catenata Lauterb. F! constricts (Szitfer)Lauterb. Schizothrix ericetorum Lemrn. Scytonema amplum W. & G. West S. burmanicum Skuja S. hofmannii C. Ag. ex Born. & Flah. S. javanicum (?) (Kiitz.) Born S. schmidtii (?I Gom. S. stuposum (Kutz.) Born. ex Born. & Flah S. tolypothricoides Kiitz. ex Born. & Flah. Scytonematopsis kashyapii (Bharadw.) Geitler Spirulina subtilissima Kiitz. 7blypothri.x distorta Kiitz. ex Born. & Flah.

Pleurocapsales Myzosarcina spectabilis Geitler Xenococcus kerneri Hansg.

Stigonematales Camptylonerna indicum Schmidle Hapalosiphon delicatulus W. & G. West H. fontinalis (Ag.) Born. H. hibernicus W. & G. West H. inteolus W. & G. West H. intricatus W. & G. West H. luteolus W. & G. West H. stuhlmannii Hieron. H. welwitschii W. & G. West Nostochopsis lobatus Wood em. Geitler Plectonema indica Dixit Stigonema aerugineum Tilden S. dendroideum FMmy Stigonema kormides (Kiitz.) Born. & Flah. S. informe Kiitz. S. mesentericum Geitler S. minutum (C. Ag.) Hass. S. panniforme Harv. ex Born. & Flah. S. turfaceum (Berk.) Cooke ex Born. & Flah.

Chlorophyta

Chaetophorales Cephaleums virescens Kunze Protococcus uiridis C. Ag. Stigeoclonium polymrphum (?) (Franke) Heering Dentepohlia area var. tenuior Briihl & Biswas Z! aurea (L.) Martius T. iolithus (L.)Wallroth T. torulosa De Wildeman Z! umbrina (Kiitz.) Born.

Chlorococcdes Ankistodesmus falcatus (Corda) Ralfs Characiurn stipitatum (Bachm.) Wde C. obtusum (?) Braun Chlorella ellipsoidea Gern. C. vulgaris Beyerinck Chlomcoccum humicola (Nag.) Rabenh. Crucigenia quadrata Morren Ooeystis borgei Snow Table 7.-Algae species list for Pico del Oeste in the Baa de Oro Natural Area* Nomenclature 0. pyriformis Prescott 0. submarina Lagerheim Pediastrum muticum var. crenulatum Prescott I! muticum Kiitz. Quadrigula chodatii (Tanner-F'iillemann)G. M. Sm Q. lacustris (Chod.) G.M. Sm Scenedesmus arcuatus var. platydisca G.M.Sm. Tetraedmn tumidulum (Reinsch)Hansg. %chiscia qranulata (Reinsch)Hansg.

Cylindrocapsales Cylindrocapsa conferta W. West C. geminella Wolle

Oedogoniales Oedogonium sp. Pithophora oedogonia (Mont. ) Wittr.

Sphaeropleales Sphaemplea annulina (Roth) C. Ag.

Tetrasporales Gloecystis major Gerneck G. wsiculosa Nlig. Sphaerucystis schmeteri (?) Chooat

Tribonematales Dibonema utriculosum (Kiitz.) Hazen

Ulotrichales Geminella interrupta 'Jhrpin Stichococcus subtilis (Kiitz.) Klercker Ulothrix aequalis Kiitz. U. variabilis Kiitz

Zygnematales Cosmarium dentatum WoUe Cosmarium sp. Cylindrucystis brebissonii var. minor W. & G. West Euastrum q. Hyalotheca undulata Nordst. Micrasterias denticulata (?) Breb. M. caimani Transeau M. floridam Transeau Mougeotia globulispom Jao Netrium digitus (Ehmb.) Itzigos. & Rothe Temnogarnetum transeaui hscott Zygnemopsis desmidioides (W. & G. west) Transeau Zygogonium ericetorum Kiitz.

Heterococcales Pemniella planctonica G. M. Sm. Pleumgaster lunaris Pascher Tetragoniella gigas Pascher

Rhyzochrysidales Chrysidiastrum catenatum Lauterb. Lagynion reductum Prescott Table 7.-Algae species list for Pico del Oeste in the Bario & On, Natural Area* Nomenclature Bacillariophyta

Centrales Biddulphia alternuns (bail.) Van Heurek B. fwus (Ehrenb.) Van Heurck Campylodiscus echeneis (?) Ehrenb. Coccimdiscus lacustris (?) Grun. Cyclotella bodanica (?) Eulenst. C. glomerata Bachm. Melosira crenulata (Ehrenb.) Kutz. M. granulata (Ehrenb.) Ralfs M. varians C. Ag. Piceratiurn semicirculare Brightw. T. undulatum Ehrenb. Pennales Achanthes hwkiana Grun. A. microcephala (Kutz) Grun. Amphora ovalis Kiitz. Anomoeoneis costata (?) (Ktitz.1 Hust. Cymbella uentricosa Kutz. Dentivuh sp. Diatoma hiernale (Roth) Heib. D. hiemak var. mesodon (Ehrenb.) Grun. D. tenue var. ebngatum Lyngb. Diatoma vulgare Bow Diatomella balfouriana Gm. Diploneis oculata (Breab.) C1. Eunotia exigua (?) (Br6b) Rabenh. E. fallux Cleve-Euler E. naegelii Mig. E. pectinalis f. elongata van Huerck E. pectinalis var. minor (Kiitz.) Rabenh. E. perpusilla (?) Grun. E. praerupta Ehrenb. E. soleimlii (Kutz.) Rabenh. Eunotia sp. E. tenel& (Gmm.) Hust. Fmgilaria breuistriata Grun. F. lapponica Grun. Frustulia rhomboides var. capitata (Mayer) Patr. F. rhomboides var. samnica (Rabenh.) De'Ibni l? rhomboides var. viridu2a (Bdb.) C1. Hantzschia amphimys (Ehrenb.) Grun. Zsthmia eneruis Ehrenb Navicula carnidensis (?) Hust. N. cineta (Grun.) C1. N. contenta Grun. N. crucicula (?) (W.Smith) Donk N. cryptocephala t?) Kiitz. Navicula spp. (3 separate species) N. tenelloides Hust. Nitzschia biacrula (?) Hohn & Hellerman N. dissipata (Kutz.) Grum. N. ltantzschiana Rabenh. N. igmmta Krasske N. parvula Lewis N. tryblwnella Hantzsch. Pinnularia sudentica Hilse l? viridis var. minor Cleve Rhopalodia gibberula (Ehrenb.) Mueller R. uentricosa (Kiitz) Mueller Stwroneis ignorata (?) Hust. Surirella ovata Kutz. lFopidoneis sp. Table 7.-Algae species list for Pico del Oeste in the Bario de Om Natural Area* Nomenclature

Pyrmphyta

Dinococcales Cystodinum cornifaz (Schilling) Klebs

Euglenophyta

Euglenales Eugleruz elastica (?) Prescott E. polymorpha Dangeard Glenodinium kulczynskii (?) (Wolosz.) Schiller Trachelomonas charkowiensis (?) Swirenko *Source: Faerster 1971

Dee fall gap with regeneration of Cecropia peltata in the Balio de On, Natural Area. Transpiration rates of dwarf forest trees were observed groups of three according to topography (ridge, slope, to be relatively low when compared to other environments and valley) at each elevation. Height of the dominant (Medina and others 1981, Weaver and others 1973). Dif- and codominant stems decreased along the gradient ferent rates were detected between primary and second- from 23 m at a 350-m elevation to 5 m at a 1,025-m ary species and between sun and shade exposures elevation, with the most and least pronounced (Weaver 1975). Moreover, rates were negatively correlated decreases apparent on ridge and valley topography, with the amount of cloud cover on the peaks. respectively (fig. 12). Although variation in tree height Tree diameter increment averaged 0.03 cmlyr, and is considerable, the tallest trees in the tabonuco forest aboveground biomass accumulation was estimated at (5600 m) are on ridges, and the tallest trees in the 0.45 t/ha/yr (Weaver and others 1986). Litterfall aver- dwarf forest (2900 m) are found in valleys. aged 3.1 t/ha/yr, 79 percent of which was leaf litter, 9 The diameters of the largest recorded stems in the percent wood litter, and 12 percent miscellaneous mate- dwarf, colorado, and tabonuco forests were about 50 rial. Leaf herbivory was estimated at 5.5 percent, or cm, 100 cm, and 95 cm, respectively. Only 32 percent of 0.13 t/ha/yr (Benedict 1976). These data yield an esti- the dwarf forest trees are 110 cm in d.b.h., whereas the mate of aboveground primary productivity of nearly comparable figures for the coIorado and tabonuco forest 3.7 thalyr (Weaver and others 1986). are 60 and 65 percent, respectively (fig. 13). The tallest Dwarf forest succession after disturbance was trees in the dwarf, colorado, and tabonuco forests mea- observed for nearly 20 years near Pico del Este. Recov- sured about 15 m, 21 m, and 28 m. Only 10 percent of ery after 6 years was characterized mainly by woody the dwarf forest trees were >9 m tall, whereas compar- sprouts, ferns, and grasses, whereas seedlings of woody able data for the colorado and tabonuco forests were 44 species were scarce (Byer and Weaver 1977). After percent and 54 percent (fig. 14). nearly 20 years, nine primary forest species comprised The mean basal area for all plots combined was 44 +- 75 percent of the trees and 85 percent of the biomass 3 m2/ha, and the mean total aboveground biomass, (Weaver 1990). Recovery was slow, and at the observed based on regression equations, was 205 rt 27 tha. rate would span about two centuries before the initial Basal area and biomass estimates for the respective aboveground biomass would be restored. forests are biased, especially for ridge plots at lower elevations, because the sampling procedure used small, Vegetation Gradient closed-canopy plots. These plots tend to have a greater number of stems than larger areas, which include nat- Thirty plots, 50 by 10 m in size (or 1.5 ha in total), ural breaks, or gaps, in the canopy. were systematically sampled in the Bafio de Oro to Species composition according to elevation, topogra- provide data on forest structure and species composi- phy, and forest type is tentatively presented in table 8. tion for all trees 24.1 cm in d.b.h. The plots ranged in Given that the entire sample of the area was limited to elevation from 350 to 1,025 m and were stratified in only 1.5 ha, this table is not intended to be used

A RIDGE 0 SLOPE 2 0 VALLEY

\ 5 h 2 9 '5 $ iu iu 2 10 Z

5

0

ELEVATION (m)

Figure 12.- The height of dominant and codominant trees by topography and elevation on closed canopy 50- by 10-mplots in the Bario de Om Natural Area. Walking Clusia grisebachiana possibly the res iuk of past hurricane impacts in the Baria de Om Natural Area.

rigorously to determine species distributions, but Forest dynamics also show changes with elevation rather is to be used as a guide. In general, the f~st30 (table 10) Weaver and Murphy 1990). Mortality rates species ranging from Pterocarpus oficinalis through in palm and tabonuco forests measured over 30 years Alchornea latifolia are principally tabonuco forest spe- exceeded ingrowth, while in the colorado forest mor- cies. The 12 species from Haenianthus salicifolius tality rates measured over 35 years were equal to through Ternstroemia luquillensis are mainly dwarf ingrowth. These differences may be due to more rapid forest species. The remaining 27 species in between are growth and competition among stems in the lower for- principally colorado forest species, or are well dis- ests. Loose litter tends to increase with elevation except tributed throughout the Bafio de Oro. in the dwarf forest. In contrast, litterfall decreases Among the larger shade tolerant species, Prestoea with elevation except in the palm forest (Frangi and montana, Micropholis garciniaefolia, and Calyco- Lugo 1985). Litter turnover rate also decreases with gonium squamulosum are well distributed in all three elevation. Standing herbivory and herbivory rate forest types. Cecropia peltata, a shade-intolerant spe- records are incomplete and thus difficult to compare. It cies, is also well distributed. Among the smaller tree appears, however, that both decrease with an increase species, Ocotea leucoxylon and Psychoteria berteriana in elevation. Diameter, volume, and biomass increment are found throughout the area. Ocotea spathulata and all decrease with elevation as does aboveground net Tabebuia rigida, shade-tolerant species normally con- primary productivity. fined to the upper two forest types, are also present in The structural and floristic impoverishment of for- the tabonuco forest. This is probably due to the high ests with an increase in elevation on small, wet, tropical rainfall that characterizes the Baiio de Oro. mountains, such as the isolated, coastal mountains in Information borrowed from several other LEF stud- the West Indies, has been attributed to the Mas- ies outside of the Baiio de Om provides insights regard- senerhebung effect, a phenomenon first recorded in the ing changes in forest structure and dynamics over the European Alps. Many investigators have proposed gradient from the 150-m LEF border to the 1,050-m ideas to account for this phenomenon in Puerto Rico mountain summits. Future studies may confirm simi- and elsewhere, among them, saturated soils and lar relationships within the Bafio de Oro. reduced root respiration (Holdridge 19671, impeded soil Structurally, the number of trees per unit area and drainage (Wadsworth and Bonnet 1951), high winds in the soil organic matter content increase with elevation summit areas, leaching of the soils combined with high (table 9). In contrast, specific leaf area, canopy height, fog incidence (Baynton 19691, reduced transpiration typical d.b.h. range, forest volume and biomass, leaf rates (Beard 1944, Leigh 1975, Odum 1968), and fog, area index, and species richness all decrease with an high soil water content, and reduced mineralization of increase in elevation. organic matter (Grubb 1971). 1,500 ...... :...: ..:.:.,:.> 1,400 ...... : ...... DWARF FOREST n.:...:;.:.:.i... DWARF FOREST

Y 0 600 COLORADO FOREST 2 d 500 C \ 400 L I. I. 2; 3 00 3 111 200 Q q I00 k' 90

HEIGHT CLASS (m)

Figure 14.- Height class distributions of trees on closed canopy 50- by 10-m-temporary plots in the tabonuco, colorado, and dwarf forests of the Baiio de Om Natural Area.

DIAMETER CLASS (cm) LEF, several permanent plots were established Figure 13. -Diameter class distributions of trees on closed canopy 50- throughout the forest to determine species composi- by 10-mplots in the tabonwo, cobrado, and dwarf forests tions and diameter growth rates 1980, Lugo and of the Balio & Om Natural ha. (Crow Brown 1981, Wadsworth 1950a, Weaver 1983). One of these, TR-1, is located at a 350-m elevation in the northern part of the Baiio de Oro. The 0.4-ha plot is Current Research Activities centered on a ridge and contains tree species charac- teristic of the tabonuco, colorado, and dwarf forests. Long-nrrn Monitoring on TR-1.- Known for- First sampled in 1946, the plot was remeasured in 1951, estry research activities began in the Baiio de Oro with 1956, 1966, 1977, and again in 1988 and 1990, just the 1937 timber cruise. The cruise records were used to before and immediately after the passage of Hurricane characterize species composition and forest structure Hugo in September 1989. With the passage of time, the and are still available at the International Institute of plot record has become a valuable chronology of Tropical Forestry. changes in species composition, forest structure, and Beginning in the mid-1940's, only a decade after the dynamics in response to Hurricane San Cipriano of passage of Hurricane San Cipriano directly over the 1932 (table 11) (Weaver 1983). W Table 8.-0cc~~rrence of tree species in the Barb de Om Natural Area by elevation, topography, and forest type.* Species are ranked from those most common at lower elevation to those most common at higher elevation

Elevation (Meters) Total Percent by topography Percent by forest typet Soecies 350 450 550 600 650 700 750 850 950 1050 NO. Percent Valley Slope Ridge Tabonuco Colorado Dwarf

Ptemcarpus officinalis Andira inermis Guatteria caribaea Ixora ferrea Laplaceaportoricensis Phyllanthus nobilis Buchenavia capitata Rneediaportoricensis Mecranium amygdalinum Hirtella rugosa Inga laurina Manilkara bidentata Meliosma herbertii Cassipourea guianensis Guarea guidonin G. ramiflora Antirhea obtusifotia ?hbebuia hetemphylla Homalium racemosum Drypetes glauca Menendezia urbanii Cordia sulcata Myrcia deflexa Ocotea moschata Eugenia stahlii Palicouma riparia Slwnea berteriana Dacryodes ercelsa Didymopanax momtotoni Alchornealatifolia Miconia tetrandra Daphnopsisphilippiana Cmtonpoecilanthus Ditta myricoides Cyrilla racemiflom Sapium laurocemsus Rondeletiaportoricensis Magnolia splendens Coniia borinquensis Prestoea mntana Bble 8. -Occurrence of tree species in the Bar% & Oro Natural Area by elevation, topography, and forest type.* Species are ranked from those most common at lower elevation to those most common at higher elevation - Continued.

Elevation (Meters) Total Percent by topography Percent by forest typet S~ecies 350 450 550 600 650 700 750 850 950 1050 No. Percent Vallw Slow Ridee Tabonuco Colorado Dwarf

Ocotea leucmylon Cecropia peltata Citharaylurn caudoturn Miconia Iaevigata Eugenia eggersii Xylosma schuaneckeanurn Miconia prasina 'lbrralbasia cuneifolin Ardisia luquillensis Micropholis garciniaefdia Psychofriaberteriann Clusia krugiana Calycogoniurn squarnubsurn Hedyosrnurn arbnrescens Byrsonima wadswrthii Myrcia fallax Miconia pachyphyllo Haenianfhus salicifdiius Marliern sintenisii Ilhbebuia rigida Grnrnrnaa'enia sintenisii Ocotea spathulata Cyothea arborea Iler sideraryloides Eugenia borinquensis Calyptranthes krugii Alsophilo bryophila Miconia sintenisii lkmstroernia luauillensis -- Number ofstems Number of stemslha

Number ofspecies SDecies oer foreat

'Survey conducted an 30 temporaty plots 50 by 10 m in size. ?Forest types: tabonurn, 360 to 600 m; Colorado, 600 to 750 m; and dwarf 850 to 1050 m. Percentages refer to proportions of species found on each topographic position or forest type. Table 9.-Comparison of stand structure for four forests within the Luquillo Mountains* Forest type Structural characteristics Tabonuco Palm Colorado Dwarf

Treeslha Canopy height (m) Typical d.b.h. range icm) Basal area (mzlha) Aboveground volume (m31ha) Aboveground woody biomass (tlha) Leaf biomass (tlha) Leaf area index (m2/m2) Specific leaf area (cmzlg) Standing herbivory (percent) Total tree species Tree specieslha Soil organic matter (tlha)

*Benedict 1976; Crow 1980; Frangi and Lugo 1985; Medina and others 1981; Odum 1970; Odum and Ruiz-Reyes 1970; Ovington and Olson 1970; Wadsworth 1950a; Weaver 1972a, 1983; Weaver and Murphy 1990. ?All trees 24 cm in diameter. *All trees 2 1cm in diameter. §Blank fields indicate missing data. aTop 25 cm of soil. **Top 100 cm of soil. ttTop 50 cm of soil.

Table 10. -Comparison of stand dynamics for four forests within the Luquillo Mountains* Forest type? Dynamic feature Tabonuco Palm Colorado Dwarf

Ingrowth (stemslhalyr) Mortality (stemslhalyr) Litterfall (tlhalyr) Leaf wood Flower Fruit Mischeous Loose litter (tlha) Herbivory rate (tlhalyr) Litter turnover rate Mean d.b.h. growth (cmlyr) Total aboveground growth Woody volume (m31halyr) Woody biomass (tlhalyr) Total aboveground net primary productivity (rlhalyr)

*Adapted from: Benedict 1976; Briscoe and Wadsworth 1970; Frangi and Lug0 1985; Odum 1970; Reagan and others 1982; Wadsworth 1951,1952; Weaver 1983; Weaver and Murphy 1990; Weaver and others 1986. tPlot elevations: tabonuco, 450 m; palm, 750 m; colorado 750 m; and dwarf 1,000 m. *Blank fields indicate missing data. $Flowers and fruits combined. able 11.-Stand table-ranking of species by density and basal area (BA) dominance on permanent plot TR-1 from 1946 through 1976 on a hectare basis 1946 Ingrowth 1946-76 Mortality 1976 Species No. of stems BA No. of stems BA No. of stems No. of stems BA Meters Meters Meters Dacryodes excelsa 215 20.93 5 0.01 30 190 24.30 me last om at ace^ Spp. 208 1.04 ....* .... 120 88 1.80 Prestonea montana 195 3.36 28 .37 40 183 3.30 Micropholis garciniaefolia 120 3.22 2 .OO 27 95 2.90 Octoea mschata 105 1.14 10 .01 55 60 .64 Calycogonium squamulosum 95 .50 5 .01 45 55 .40 Sloanea berteriam 82 1.00 10 .03 40 52 .3 1 Didympanax mrototoni 75 .75 ...... 20 55 2.10 Cordia borinquensis 70 .21 5 .01 55 20 .07 Hirtella rugosa 62 .25 22 .04 13 7 1 .30 Psychotria berteriana 60 .12 ...... 60 ...... Cordia sulcata 52 .19 ...... 34 18 .12 Laplacea portoricensis 50 .32 ...... 38 12 .13 Cecropia peltata 48 .45 ...... 38 10 .36 Meliosma herbertii 32 .27 12 .02 4 40 .37 Inga laurina 28 .31 ...... 13 15 .44 Alchornea latifolia 28 .30 ...... 12 16 .60 Magnolia spkndem 25 2.51 ...... 12 13 2.60 Rheedia portoricensis 25 .10 15 .02 2 38 .11 Manilkara bidentata 25 .08 2 .00 2 25 .18 Wbuiaheterophylla 22 .ll 5 .01 14 13 .09 Matayba domingensis 18 .20 ...... 18 .77 Cyrilla racemiflora 15 2.91 ...... 4 11 3.10 Bucherrwia capitata 12 1.30 ...... 2 10 2.50 Homalium racernosum 12 .44 ...... 12 .87 Cyathea arborea 10 .07 ...... 10 ...... Eugenia borinquensis 8 .40 ...... 8 .50 Byrsonima wadsworthii 8 .35 ...... 8 .40 Andira inermis 8 .09 ...... 3 5 .10 lktragastris balsamifem 8 .03 ...... 8 .07 Myrcia splendem 8 .02 ...... 8 ...... Hedyosmum arborescens 8 .01 ...... 8 ...... Alchorneopsis portoricensis 5 .10 ...... 5 .45 Casearia sylvestris 5 .O1 2 .oo 5 2 .oo 2 00 Daphmpsis philippiam 5 .01 2 .OO 5 . Beilschmiedia penduln 2 .37 ...... 2 1.oo Guakteria caribma 2 0.16 ...... 2 0.18 Solnnum rugosum 2 .02 ...... 2 ...... Croton poecilnnthus 2 .01 ...... 2 .03 Byrsonima coriaceae 2 .01 ...... 2 .02 Sapium laurocemsus 2 .01 ...... 2 ...... Phyllanthus nobilis 2 .01 ...... 2 .00 Myrcia dew 2 .00 ...... 2 ...... Quamribaea turbinata 2 .OO 2 0.00 .... 4 .01 2 Guarea ramiflorn 2 .OO ...... oo Ocotea leucaxylon 2 .OO ...... 2 ...... 2 Byrsonirna coriacea 2 .OO ...... Antirhea obtusifolia 2 .OO ...... 2 .00 Oxandra laurifdia ...... 8 .01 .... 8 .01 Guareaguidonia ...... 2 .00 .... 2 .oo Unknown ...... 2 .oo .... 2 .oo 1188 51.13 Mean total 1778 43.69 139 0.54 729

*Blank fields indicate missing data. The 30-year partial record shows stand composition in Diameter class distributions also indicate changes 1946 and 1976. Mortality exceeded ingrowth, and the over time (fig. 15). Stems in the smallest two d.b.h. number of stems decreased considerably over the period classes, between 4.1 and 19.9 cm, decreased by 58 per- of measurement. Small secondary trees such as the cent and 21 percent, respectively, between 1946 and Melastomatacae and Psychoteria berteriana disappeared 1988. In contrast, the stems in the next two largest completely. Larger secondary species such as Cecropia d.b.h. classes, between 20.0 and 39.9 cm, increased 23 peltata and Didymopanax morototoni, and several percent and 57 percent, respectively. Fluctuations in Melastomataceae, decreased considerably in numbers. classes 240 cm are less evident. These structural Table 12 shows a 30-year record of diameter growth changes reflect growth after the 1932 hurricane. After by species for all stems that survived the period. A Hurricane Hugo, the number of stems decreased in all gradual slowing of growth is apparent as the trees age diameter classes, most notably in those between 4.1 and the stand closes during recovery. and 19.9 cm (fig. 15).

Table 12. -Mean annual d.b.h. increment by species from 1946 through 1976 on permanent plot TR-I for all trees that survived the entire period and range of d.b.h. by species in 1946 Mean annual diameter increment No. D.b.h. range Species cv* 1946-51 1951-56 1956-66 1966-76 1946-76 of stems 1946 ...... Centimeterslyear ...... Percent+ Centimeters Dacryodes ercelsa 0.22 0.13 0.14 0.16 0.16 87 74 4-96 Mehstomataceae spp. .31 .22 .24 .14 .21 69 35 4-25 Prestoea montaruz .03 .01 .02 .02 .01 175 62 10-20 Micropholis garciniaefolia .ll .02 .06 .04 .05 98 37 6-37 Ocotea moschata .14 .07 .08 .05 .08 67 19 4-28 Calycogonium squamulosum .10 .05 .08 .03 .06 110 20 4-22 Sloanea berteriana .10 .08 .12 .06 .09 84 17 4-9 Didymopanojc mrototoni .62 .42 .28 .12 .31 64 22 5-22 Cordia borinquensis .02 .00 .02 .02 .01 118 6 4-10 Hirtella rugosa .03 .02 .03 .02 .02 98 20 4-13 Cordia sulcata .06 .02 .05 .04 .04 130 7 4-1 1 Laplacea portoricensis .24 .09 .12 .08 .ll 90 5 4-12 Cecropia peltata .80 .25 .38 .15 .35 16 4 6-15 Meliosma herbertii .10 .06 .09 .04 .07 100 11 4-23 Inga laurina .15 .15 .22 .10 .14 92 6 6-21 Alchornea latifolia .49 .29 .24 .03 .21 99 6 7-19 Magnolia splendens .10 .12 .05 .08 .07 73 5 7-67 Rheediaportoricensis .03 .00 .03 .02 .02 140 9 4-9 Manilkara bidentata .12 .08 .15 .08 .10 54 9 5-9 'Ihbebuia heterophylla .02 .02 .O1 .05 .02 107 3 5-15 Matayba domingensis .50 .38 .42 .25 .36 36 7 5-20 Cyrilla racemiflom .22 .21 .18 .18 .19 64 4 39-74 Buchenavia capitata .79 .62 .45 .38 .51 34 4 27-56 Homalium racemosum .38 .21 .32 .16 .25 84 5 8-37 Eugenia borinquensis .12 .08 .15 .02 .09 87 3 23-29 Byrsonima wadsworthii .02 .02 .10 .02 .04 58 3 11-34 Andira inermis .15 .02 .10 .05 .08 24 2 12-15 Dtragastris balsamifera .07 .02 .07 .20 .ll 42 3 5-12 Alchorneopsis portorkernis .85 .65 .80 .35 .61 7 2 7-2 1 Beilschmiediapendula .60 .80 .58 1.43 .92 .... 1 43 Guatteria caribaea .05 .10 .12 .OO .06 .... 1 28 Crotonpoecilanthus .10 .lo .22 .16 .16 . . . . 1 7 Byrsonima coriacea .15 .OO .15 .10 .10 . . . . 1 7 Phyllnnthus rwbilis .05 .05 .02 .08 .05 .... 1 6 Quararibaea turbinata .05 .05 .OO .00 .02 .... 1 5 Guarea ramiflora .00 .OO .02 .OO .01 .... 1 5 Antirhea obtusifolia .05 .00 .02 .02 .02 .... 1 4 MeanlTotal* 0.125 0.075 0.085 0.058 0.080 .... 418 4-96 0.134 0.085 0.095 0.065 0.088 138 356 4-96

*CV = coeMicient of variation. tBlank fields indicate missing data. *Top row includes plam Prestoea montana; bottom row excludes palm. I D.B.H. CLASSES (fm) I

YEAR

Figure 15. -Diameter class distributions in 7 differentyears on long-term plot TR-1in the Barto & Om Natural Area. The numbers in the declining sequence from 713 to 332 refer to total stems in the plot.

Phenology nail.-A trail was established through In December 1990, the study was expanded to the east fork of the Rio Marneyes in February 1987 to include trees on a permanent plot that had been dis- monitor the phenology of colorado forest vegetation. turbed by Hurricane San Cipriano in 1932 and thinned Ninety-eight individual plants were originally selected: in 1946. Increment borings and ring counts of trees on 14 were Marcgravia sintinisii or Clusia gundlachi, sites with known past disturbance will be used as an common forest vines, and 84 were of 15 tree species additional test of the hypothesis that the number of with d.b.h.'s between 4.3 and 110.0 cm (table 13). rings is indicative of tree age in Cyrilla. Simultaneous Monitoring is done twice monthly. The quantity of monitoring of carbon dioxide exchange of Cyrilla leaves flowers, leaves, and fruits, each rated from 1through 4, along with that of xylem water potential is being done are recorded for each plant. Fruit size and ripeness are to clarify the relationship between these parameters. also noted, as are the number of individuals of each Minority Research Program. -Eight separate bird species found using the plants. Unfortunately, sev- experiments aimed at determining the influences of eral plants were damaged by Hurricane Hugo. These climate, soil fertility, and genome on plant productivity should be replaced to maintain the initial representa- are being conducted in the dwarf forest near the border tion of plants. of the Baiio de Oro (fig. 2). The research consists of: Ring Formation in Cyrilla Racemiflora. -A tree growth in fertilized versus control plots, under- study was initiated in January 1989 to determine the story responses to fertilization, fine root biomass and nature of ring formation in Cyrilla racemiflora. One of production observations, litterfall and litter chemistry, the four sites selected for the study borders the Baiio de nutrient cycling via throughfall, nitrogen mineraliza- Oro. Among the parameters being monitored at the tion and nitrification, wind damage to forest trees, and Baiio de Oro site are rainfall, temperature, branch a transplant experiment. elongation, flowering and fruiting, leaf formation and The tree growth in fertilized versus control plots was leaf drop, xylem water potential, and xylem cell forma- originally designed to evaluate the effect of nutrient tion. The study spanned one dry season extending from availability (N-P-K plus micronutrients) on forest pro- January to late June 1989, with further monitoring in ductivity such as diameter increment, twig growth,.and October and December 1989 and in June 1990. As sam- new leaf development. Given that Hurricane Hugo pling continues and the patterns observed in the first damaged the plots, the experiment now deals with a year are tested against future growth, the periodicity forest recovering from disturbance rather than with a of growth ring formation should become clearer. mature forest. The revised experimental design places Table 13. -Species inclhd in the phenological study in the East Fork watershed of the Rio Mameyes

Number of D.b.h.* Species individuals Minimum Maximum

Calycogonium squamulosum 1 12.0 12.0 Clusia gundlachii + 2 ...... Dacryodes 0u:elsa 10 26.0 85.0 Eugenia stahlii 2 24.0 25.0 Haenianthis salicifolius 5 8.0 55.0 Inga laurinn 5 16.0 75.0 Laplacea portoricensis 1 13.0 13.0 Magnolia splendens 10 41.0 85.0 Marcgravin sintenisiit 12 ...... Mat* domengensis 5 34.0 43.0 Micropholis garciniaefolia 11 22.0 55.0 Ocotea portoricensis 1 18.0 18.0 0.spathulata 3 19.0 40.0 Prestoea mntana 10 11.5 19.0 Psychotrai berteriana 1 4.3 4.3 Rheedia portoricensis 8 5.0 14.0 Sloanea berterinna -11 15.0 110.0 Total 98 *Blank fields indicate missing data. Vines;all remaining species are trees.

greater emphasis on indices of productivity such as Wind damage to trees is being assessed on forest canopy recovery (leaf area index), sprouting, and plots established before Hurricane Hugo to answer recruitment and growth of seedling and saplings. four questions: (1) Can damage be predicted by either Understory responses to fertilization are being abiotic factors (for example, aspect) or biotic factors assessed on treatment and control quadrats located (for example, tree diameter)? (2) Is initial tree recovery within the fertilized and control plots. Vegetation cover, related to damage? (3) Do tree species recover from height, and basal diameters of marked tree seedlings damage at different rates? (4) Does the forest recover are being measured every 6 months. via species turnover and succession or via direct Fine root biomass and production are being observed regeneration of canopy species? on the treatment and control plots. Six cores are The transplant experiment is designed to explore two sequentially taken in the upper 10 cm of mineral soil questions: (1) Are there genetic differences in growth and litter layers on each plot at 2-month intervals. characteristics between populations of tropical plant Changes in the live and dead fine root mass between species growing at low and high elevations? (2) Does sampling dates are used to determine root production, wind affect the growth of plants in the dwarf forest? mortality, and decomposition in each experimental Reciprocal transplants of clones of key forest species plot. are used to detect genetically determined differences in Litterfall and litter chemistry are being examined to productivity between seedlings in the dwarf forest and determine the influence of nutrient availability on the those at lower elevations in the LEF. The effect of wind production of canopy litter, its nutrient concentrations, on productivity in the dwarf forest is being examined and the efficiency of nutrient use. Litter derived as a by comparing growth in plots protected by barriers result of the hurricane is also being examined in the versus growth in exposed plots. same manner. Litter baskets are sampled every 2 Water Chemistry. -Weekly sampling of streamflow weeks, and the collections are sorted into fractions and was initiated just above the USGS (U.S. Geological analyzed for nutrients. Fresh leaf samples of a common Survey) gauge at Puente Roto in May 1989 as part of dwarf forest tree, Tabebuia rigida, are simultaneously the long-term ecological research in the LEF. The pur- collected on each plot. pose of the study is twofold: first, to quantify dissolved Nutrient cycling via throughfall is being assessed by and fine particulate exports from the Rio Mameyes using 3-day sampling periods twice monthly on the watershed, which includes the Bisley experimental treatment and control plots. Nitrogen mineralization watersheds, and drainage from the Baiio de Om;and and nitrification are being estimated by in situ incuba- second, to determine the effects of watershed scale on tion of intact soil cores every 6 months. exports by comparing the Puente Roto data with those from smaller watersheds in the same basin. The dis- Vertebrates solved chemistry parameters being measured are: pH, One species of fish was observed but not identified. ortho-P04, NO,-, NH4+, organic C, organic N, C1-, This was probably the green stream goby (Sicydium SO4-2, SiO,, Na+, K+, Ca+2, and Mg+2. Particulate plumieri), a diadromous fish reported to be in the head- measures include N, C, and total sediments. Observa- waters of the Rio Mameyes (Erdman 1986, Wiley and tions will continue for several years. Bauer 1985). The goby is common in streams of the West Indies (Erdman 1961). FAUNA Eleven of the 14 reported for the LEF (Brown and others 1983) were collected. These included From August 31, 1984, through February 8, 1985, a 1 toad and 10 endemic frogs of the Eleutherodac- general survey of animal species was conducted in the tylus. Of the 13 reptiles identified, 2 were geckos, 8 Baiio de Oro by the University of Puerto Rico Biology were lizards (mainly of the genus Anolis), and 3 were Department. The purpose was to determine the diver- snakes. Epicrates inorncltus, the Puerto Rican boa, is sity and distribution of the fauna in each of the four classified as a rare and endangered species. forest types and in the streams. Samples were collected Twenty-one of the 66 species of on the LEF in each of the four forest types and from the streams checklist (Wiley and Bauer 1985) were observed during flowing out of the upper reaches of the Rio Mameyes. the survey. Other species reported by qualified person- The results, based on observations made at 13 sampling nel have been added to the list (table 15). Two intro- stations (fig. 2), are shown in tables 14 and 15. duced mammals, the mongoose and the black rat, were

%ble 14.-Animal species recorded in the Bario de On, Natural Area (except bird spec*) Habitat type' Classification Endemic* TCPDW Phylum Platyhelminthes Class nr- Order Tricladida Geoplanidae 1. Geoplana sp.

Phylum Nematoda Class Adenophorea (Aphasmidea) Order Dorylaimida Family Dorylaimidae 1. Dorylaimus sp. Class Secernentea (Phasmidea) Order Qlenehida Family Aphelenchoididae 2. Aphelenchoides sp. Family Heteroderidae 3. hiebidogyne sp.

Phylum Annelida Class Oligochaeta order Haplotaxida 1. Haplotoxid sp. 1 (giant form) X 2. Haplotoxid sp. 2 (violet form) XXX 3. Haplotoxid sp. 3. (white form) X Class Hirudinea Order (?I Family (?) 4. Hirudinid sp. 1. (terrestrial form)

Phylum Class of Gastropods Subclass Prosobranchia Order Archaeogastropoda Family Helicinidae 1. Alcadin alta 0 X 2. A. striata 0 XXXX Table 14.-Animal species recorded in the Bario de Om Natural Area (erccept bird species)-Continued Habitat typet Classification Endemic* TCPDW Order Mesogastropoda Family Cyclophoridae 3. Megalomastoma croceum 4. M. uerruculosum Family Pomatiidae 5. Chondmpoma yunkei Subclass Order Family Bulimulidae 6. Gaeotis nigrolineata Family Camaenidae 7. Camcolus caracdln XXXX 8. Polydontes acutangula X X 9. l? luquillensis XXXX Family Clausiliidae 10. Nenia tridens Family Haplotremidae 11. Austrosolenites alticola Family Oleacinidae 12. Oleacina glabm 13. 0. playa 14. Varicelln portoricensis Family Sagdidae 15. Pldysuccinea portoricensis 16. Succinea hyalina Family Subulinidae 17. Obeliscus terebraster Order Systellommatophora Famly Verunididae 18. Vagragrnulusplebleius

Phylum Onychophora Family Peripatidae 1. Peripatus juanensis

Phylum Arthmpoda Subphylum Class Order Amblypygi Famly Phrynidae 1. Phrynus longipes Order Araneae Suborder Orthognatha Family 2. Psalistops corozali XXX Family Dipluridae 3. Accola spirwsa XXXX Famly Theraphosidae 4. hie* laeta X X 5. cyrtopholis portoricae X 6. Ischrwcolus cukbrae XXX 7. Stichophtus culebrae X Suborder Labidognatha Division Cribellata Family Uloboridae 8. Miagmmmopes ciliatus XXXX 9. M. mditus X Division Acribellata Family Anyphaenidae lo. Wulfila tropica 11. U! mmropalpus Family Araneidae Subfamily Gasteracanthinae 12. Gastermantha tetmcanthn Table 14. -Animal species recorded in the Bario de Oro Natural Area (except bird species)- Continued Habitat type+ Endemic* Classification TCPDW Subfamily Araneinoe 13. Edricus crassicauda X X Subfamily Metinae 14. Leucage regni 0 XXX 15. L. venusta X X 16. Pseudometa hameta X X Family Clubionidae 17. Corinna jayuyae 0 x X 18. C. abnormis 0 X Family Ctenidae 19. Oligoctenus ottleyi 0 X Family Pholcidae 20. Modisimus ccwaticus 0 X X X 21. M. modanus 0 X X X 22. M. s~oculotus 0 X X 23. M. signatus 0 XXXX Family Salticidae 24. Corythalia glorim 0 X X X 25. Emanthis portoricensis 0 XXXX Family Selenopidae Family Sparassidae 27. Pseudosparianthis jayuyae 0 X 28. Stassina portoricensis 0 XXXX Family Tetragnathidae 29. Tetragnatha tenuissima X X Family Theridiidae 30. Lithyphantes septemmaculotus XXX Family Theridiosomatidae 31. Wendilgardin theridionina 0 X X Family Zoridae 32. Zorid sp. 1 X X Order Opiliones Suborder Laniatores Family Phalangodidae 33. Metapellobunus unicolor 0 X 34. Pseudomitmcems minitus 0 XX Order Scorpiones Family Buthidae 35. Titus obtusus 0 X X X Subphylum Crustacea Class Malacostraca Order Decapoda Family Atyidae 1. Atya lanipes 0 X X 2. Micratyapoeyi X X 3. Xiphocaris elongata X X Family Palaemonidae 4. Macrobrachium carcinus X X Family Pseudothelphusidae ilobocmc sinuatifmm 0 Order Isopoda Family Cubaridae 6. Sphaemniscus portoricensis X X Family Oniscidae 6. Philocia richmndi XXXX 7. Synumps granulotus XXXX 8. Rhysotus turgifmns XXX 9. Porcelloides pruinosus X Subphylum Uniramia Chss Chilopoda Subclass Anamorpha Order Scutigemmorpha Family Scutigeridae 1. Antillona portoricensis Table 14.-Animal species recorded in the Bario de Om Natural Area (wept bird species)- Continued Habitat type+ Endemic* Classification TCPDW Subclass Epimorpha Order Scolopendromorpha Family Cryptopidae 2. Cryptops bivittatus XXX 3. Newportia longitarsis X 4. Newportia n. sp. (M.S.) 0 XXXX 5. Newportia n. sp. (M.S.) 0 XX 6. Newportia sp. (juveniles) X 7. Scolopocryptops ferruginew 0 XXXX 8. S. melamstomus 0 X X Family Scolopendridae 9. Scolopendra akernans 10. Otostigmus caraibicus Order Geophilomorpha 11. Geophilomorph sp. 1 12. Geophilomorph sp. 2 13. Geophilomorph sp. 3 14. Geophilomorph sp. 4 15. Geophilomorph sp. 5 Class Diplopods Subclass PeniciUata Order Polyxenida Family Lophoproctidue 1. Lophoturus niveus 2. hphoturus sp. Subclass Pentozonia Order Glomeridesmida Family Glomeridesmidae 3. Glomeridesmus marmoreus XXXX Order Polydesmida Suborder Polydesmidea Family Pyrgodesmidae 4. Docodesmus vidalis 5. Docodesmus sp. 6. lomus incisus 7. Iomus sp 8. Liomus obscurus 9. Liomus sp Family Chelodesmidae 10. Ricodesmus stejneri Family Fuhrmannodesrcidoe 11. Cryptogonodesmus rolleis Family Haplodesmidae 12. Cylindrodesmus caraibicus Order Spirobolida Family Spirobolellidae 13. Spirobolellus richmondi XXXX 14. Spirobolellus n. sp. 1 X X 15. Spirobdellus n. sp. 2 Order Spirostreptida Family Pseudononnolenidae 16. Epinannolene trinidadensis 17. Epinannolene sp. 18. Epinannolene sp. Order Stemmiulida Family Semmiulidae 19. Prostemmiulus n. sp. 1 20. Prostemmiulus n. sp. 2 21. Prostemmiulus sp. 1 Order Siphonophorida Family Siphonophoridae 24. Siphonophora portoricensis Table 14.-Animal species recorded in the Bario de Oro Natural Area (except bird species)-Continued Habitat type+ Classification Endemic* TCPDW

Class Symphyla Family Scutigerellidae 1. Hanseniella sp X Class Inseda Order Orthoptera Family Blattidae 5. Pelmatosilpha coriacea XXX 6. Neoblatella borinquensis XXXX Order Isoptera Family Termitidae 19. Nasutitermis costalis Family Kaotermitidae 21. Glyptotermes rubescens Order Hemiptera Family Notonectidae 29. Buenoa rnacrophthalrna Family Veliidae 30. Rhagovelia collaris Order Coleoptera Family Scarabeidae 31. Phyllophaga yunqueana Order Diptera Family 'hchinidae Ormia punctata Order Family Danaidae 41. Damsplerippus Family Megalopygidae 43. Megalo~zygekkrgii Family Satyridae 44. Cdisto nubila Family Sphingidae 45. Herse cingulota Order Hymenoptera Family Apidae 46. Apis rnellifem Family Formicidae Subfamily Dolichoderinae 47. Iridonynnex dkus Subfamily Formicinae 48. Myrmelachista ramdorum 49. Pardrechina longicornis Subfamily Myrmicinae 50. Macromischa isabellae 53. Solenopsis geminata Subfamily Ponerinae 57. Ponem opaciceps (Juan H. Opaciceps) Family Psarnmocharidae 58. Pepsi ap.

Phylum Chordata Class Osteichthyes Order Family 1. Unidentified sp. obs. Class Amphibia Order Anura Family Bufonidae 1. Bufi marinus Family Leptodactylidae 2. Eleutherodactylus coqui 0 XXX 3. E. eneidae 0 X 4. E. portoricensis 0 X 5. E. richmondi 0 X 6. Leptodactylus albilnbris 0 X Tmble 14.-Animal species reconled in the BaiLo de On, Natural Area (except bird species)-Continued Habitat type+ Classification Endemic* TCPDW Class Reptilia Order Squamata Suborder Sauria Family Gekkonidae 1. Sphaerodactylus khberi 2. S. macrolepsis grandisquamis Family Anguidae 3. Diploglossus pleei Family Iguanidae 4. Anolis c. cristatelus 5. A cuuieri 6. A. ewrmani 7. A. krugii 8. A. gundlochi 9. A. stratulus 10. A. occultus Suborder Serdentes Family Boidae 11. Epicrates inornotus Family Colubridae 12. Alsophis portoriensis 13. Arrhyton eriguum stahli Class aves* Class Mammalia Order Carnivora Family Viverridae 1. Herpestes javanicus Order Rodentia Family Muridae 2. Rattus raftus

*Species endemic to Puerto Rico indicated by 0. +Habitattypes: T = tabonuco forest; C = colorado forest; P = palm forest; D = dwarf forest; and W = fresh water. X indicates in which habitat species occurs. *Refer to Table 15.

also found. Eleven species of native bats are known to composition, population levels, size of the home range, live in some part of the LEF (Brown and others 1983, bat numbers, fidelity to feeding areas, commuting dis- Starrett 1962)' but none were observed during the sur- tances traveled, and demographic structure were inves- vey. tigated. Bat Study.- One-half of Puerto Rico's 14 bat spe- Black Rat Study. - Predation of Puerto Rican par- cies are found in the tabonuco forest (Willig and Gan- rot eggs by black rats (Raitus rattus), observed years non 1991). Stenoderma rufum, a frugivorous species ago (Rodriguez-Vidal 1959), prompted an investigation endemic to Puerto Rico and the U.S. Virgin Islands, of rat reproductive chronology, population fluctuations, comprises at least 25 percent of the individuals within and habitat use in the vicinity of active nesting sites the LEF's tabonuco forest. Other species include between 1982 and 1985 (Walker Layton 1986, Zwank Artibeus jamaicensis, a frugivore, and Monophyllus and Walker Layton 1989). Peak sexual activity occurred redmani, a nedivore. in June with peak populations observed from July The foraging movements of bats are instrumental in through September. Density estimates ranged from 70 the spatial and genetic structure of plant communities to 280 rats per hectare with the lows recorded in late through the dispersal of seeds and pollen. Moreover, winter and early spring prior to the breeding season. they respond to changes in the structure and species Radio tracking and snap trapping in trees and on the composition of the forest after major storm events. ground indicated that rats appear to be primarily Hurricane Hugo had numerous effects on bat popula- arboreal during daylight hours and spend time on the tions. Artibeus jamaicensis and S. rufurn decreased in ground at night. Snap trapping at three different eleva- numbers and M. redmani increased. The major objec- tions in the Bafio de Oro indicated denser rat popula- tive of the study was to determine the effects of the tions in the dwarf forest than in either the colorado or hurricane on bat ecology. Specifically, the community tabonuco forests. Table 15.-Checklist of birds in the Bario a% Om Natural Area Status Occurrence Habitat Common English name Common Spanish name Scientific Name in LEF* in LEFS preference** Green-backed heron Martinete Butorides striotus T c T,C,[RI Sharp-shinned hawk* Halc6n de Sierra Accipiter striotus R U T,C Broad-winged hawk* Guaraguao de Bosque Buteo platypterus R c T,C Red-tailed hawk Guaraguao Colirrojo B. jamaicensis R c T,C,P,(D) Merlin Halc6n Migratorio Falco columbarius T u T,C,(P) Peregrine falcon Halc6n Peregrinus I? peregrinus T u T,C,(P) Spotted sandpiper Playero Coleador Actitis macularia T c T,C,P, CRI Scaly-naped pigeon Paloma Turca Columba squamosa R C T,C,P,D Ruddy quail-dove Paloma Perdiz Rojiza Geotrygon montana R C T,C,P,Plant Puerto Rican parrot? Cotorra de Puerto Rico Amazon vittota R R T,C,P Puerto Rican lizard-cuckoot Pajaro Bobo Mayor Saumthera uieilloti R C E,Plant, T,C,P,D Puerta Rim screech-owl? Mucaro de Puerto Rim Otus nudipes R C T,C,P,Plant Black swift Vencejo Negro Cypseloides niger T c T,C,P,D Antillean mango Zumbador Dorado dominicus R R E,Plant Gwn mango* Zumbador Vefde A. viridis R c T,(c) Puerto Rican emerald* Zumbadorcito de Puerto Rico Chlorostilbon rnaugaeus R c (T),C,P,D Puerto Rican todyt San Pedrito lbdus micanus R C T,C,P,D Puerto Rican woodpecker+ Carpintem de Puerto Rim Melamrpes portoricensis R c Pht,T,C,P,(D) Gray kingbird Pitirre 7)rannus dominicenszs R U E,Plant Cave swallow Golondrina de Cowas Hirundo fulva T U E Red-legged thrush Zorzal de Patas Coloradas 'Iknlus plumbeus R C E,Plant,T,(C) pearly-eyed thrasher . Zorzal Pardo Margamps fuscatus R C Plant,T,C,P,D Black-whiskered vireo Julib Chivl Vireo altilopuus R C E,Plant,T,(C) Golden-winged warbler Reinita Alidorada Vermivora chrysoptera T R T,(C) Northern parula Reinita Pechidorada Parula americana T C E,Plant,T,C,P,D Magnolia warbler Reinita Manchada Dendmica rnagndia T U Plant,z,C Cape May warbler Reinita Tigre D. tigrina T u Plant,T,C Black-throated blue warbler Reinita Azul D. c~rulescens T C Plant,T,C PD Elfin Woods warbler? Reinita de Bosque Enano D. angelae R U C,P,D- -' ' Black-and-white warbler Reinita Trepadora Mniotilta vah T U Plant,T,C,P,D American redstart Candelita Setophaga ruticilla T C Plant,T,C,P,D Ovenbird Pizpita Dorada Seiurus aurocapillus T U Plant,T,C Louisiana waterthrush Pizpita de Rlo S. matacilla T c --T,C, P,lRI Bananaquit Reinita Comun Coereba hln R C Plant,T,C,P,D Antillean euphonia Canario del Pais Euphonia musica R C T,C,P,D Stripe-headed Reina Mora Spindalis zenn R C Plant,T,C,P,D Puerto Rican tanagert Llorosa Nesospingus speculiferus R c (T),c,P,E Black-faced grassquit Gorri6n Negro Tiaris bicolor R U (Pht),E Puerto Rican bullfinch* Come Name de Puerto Rico Lcaigil2a portoricens~s R C Plant,T,C,P,D

* = Endemic Subspecies. t = Endemic Species. *LEF = Luquillo Experimental Forest; status: R = resident, T = transient or migratory. sOccurrence in national forest: C = common; U = uncommon; R = rare. **Habitat preference: plant = plantation; E = edge of forest at interface with pastures, crop land or fallow land; T = Tsbonuco Forest; C = Colorado Forest; P = Palm Forest; D = Dwarf Forest (Elfin Woodland); R = River edge; brackets 1 I denote specific habitat used within a forest zone; parentheses ( ) denote habitat where species is much less common than other areas given; underlined habitat type is area in which species is most often found.

Puerto Rican Parrot Studh.-A notable decline observations of their daily habits - territorial and feed- in the population of Puerto Rican parrots after the ing behavior using radio telemetry techniques, selec- mid-1950's led to an intensive investigation of the spe- tion of nesting sites, egg laying, incubation, and cies and its habitat. The West, Central, and East Fork fledging, among other topics -was recently published watersheds of the Rio Mameyes, located in the upper (Snyder and others 1987). Observations of the parrot reaches of the Baiio de Oro, comprise traditional parrot and iter habitat continue today. habitat. Snyder (1978) disclosed that a lack of good FHture studies of the Puerto Rican parrot will nesting sites throughout the colorado forest forced the involve the foraging ecology of breeding and nonbreed- parrots to use inadequate sites, which subsequently led ing territorial pairs and observations of captively bred to reproductive losses. The Puerto Rican parrot mono- birds after their release. About 200 trees were identi- graph, summarizing nearly 20 years of continual fied with potential nesting cavities in the Baiio de Oro Parrot research blind and nesting boxes within the Baa de Om Natural Area. in the mid-1970's. The impact of Hurricane Hugo on in colorado forests where it competes with the parrot parrot habitat in general, and on the availability of for nesting sites. Several experiments with nest boxes these tree cavities in particular, will be investigated as of different depths, designs, and physical locations well. within parrot habitat provided guidelines for mitigat- Other Bird Species Studies. - Transect studies of ing competition between the species. birds were made along the Pico del Este Road and on One of the study sites for determining the effects of the Rio de la Mina trail (Kepler and Kepler 1970) at the ectoparasites on the growth and development of pearly- highest and lowest elevations in the Baf~ode Oro. Bird eyed thrashers was located within the Bafio de Oro (fig. diversity in the LEF was considered to be lower than 2). The reproductive success of the thrashers was that in the dry Guanica Forest in southwestern Puerto greatly reduced as a consequence of warble fly (Phi- Rico. lornis deceptivus) parasitism, which was heavy as a A new species of Parulidae (Dendroica angelae), result of an apparent increase in the thrasher's density endemic to Puerto Rico, was reported from the LEF's (Arendt 1983, Uhazy and Arendt 1986). Parasitized dwarf forest (Kepler and Parkes 1972). The species is nestlings either died or demonstrated different growth confined to the LEF's upper forests, including the Bafio patterns depending on the timing of the infestation and de Oro, and has also been reported in Maricao Forest in the extent of parasitic attack (Arendt 1985a). The western Puerto Rico. This bird's isolated habitat, impact of parasitic attacks was less on adults than on restricted range, and similarity to the black-and-white nestlings (Arendt 1985b). warbler were factors responsible for its late discovery. Some of the observations on the breeding biology and Recommended birding sites for the LEF include the diet of red-tailed hawks (Buteo jamaicensis) were also Yokahu Tower and the Big nee Trail on the Baiio de made in the Baiio de Oro (Santana and Bmple 1988). Oro's western border, the Pico del Este Road along its Observations on the biology of the sharp-shinned hawk southern highpoints, and the Bisley/Mameyes River (Accipiter striatus) continue today. Valley at the northern base of the Baiio de Oro Wiley Beginning in September 1989, after the passage of and Bauer 1985). Additional bird species seen from Hurricane Hugo, point counts of forest bird species these vantage points as well as by qualified observers were initiated in the Baiio de Om. Fifteen stations elsewhere within the Bafio de Oro have been incorpo- 100 m apart are being used to tally North American rated into the survey list (table 15). migrants and determine their population densities and The pearly-eyed thrasher (Margarops fuscatus) was fluctuation over time. not abundant in the upper LEF prior to 1950 (Snyder Anoline Lizard Studies. -In the early 1960's, the and Taapken 1978). Presently, the thrasher is common distribution of anoline lizards was studied in the vicinity of an 800-m elevation in the LEF (Rand 1964), Classified Plant and Animal Species probably just west of the B&o de Oro. 75.pical perch heights, perch diameters, and shade conditions were Several of the plant and animal species recorded in recorded for Anolis euermanni, A. gundlachi, and A. the Baiio de Oro have been classified by the U.S. Fish krugi to determine how differences in structural and and Wildlife Service, the Commonwealth Department microclimatic preferences result in spatial separation of Natural Resources, or the Forest Service as rare, among species. endangered, threatened, or sensitive. The Federal list Today, the distribution of 'anoline lizards, as well as of threatened and endangered species in Puerto Rico the effects of Hurricane Hugo on anoline lizard com- (Delgado-Mendoza and others 1990) contains the munities, are being studied along an elevational gra- Puerto Rican parrot (Amazona vittata), the Arctic pere- dient from 500 to 1,000 m in the LEF. The 800- and grine falcon (Falco peregrinus tundrius), and the 900-m sites are situated in the Bafio de Oro. The main Puerto Rican boa constrictor (Epicrates inornatus). objectives of the study are to assess the composition, Additional species listed by the Commonwealth Depart- density, and diversity of anoline lizards, to determine ment of Natural Resources as threatened or structural niche dimensions for all species, and to mea- endangered are the sharp-shinned hawk (Accipiter sure niche breadth and overlap at each elevational striatus vendor) and two species of tree frogs, Ek- level. utherodactylus eneidae and E. karlschmidti (Delgado- Frog Diversity Study. - Beginning in February Mendoza and others 1990). 1989, a 200-m transect has been sampled for frog den- Animal species classified as sensitive by the U.S. sity and abundance in the vicinity of the southwestern Department of Agriculture, Forest Service (1990), boundary of the Bafio de Oro. Regular monitoring for include the three aforementioned species listed by the the most common species includes sampling for adult Commonwealth as well as the broad-winged hawk sizes, presence of juveniles, sex determination, and (Buteo platypterus brunnescens) and the elfin woods breeding activities, including assessment of egg warbler (Denclroica angelae). Plant species on the sen- clutches. An attempt will also be made to determine the sitive list are: Eugenia eggersii, Laplaceaportoricensis, effects of Hurricane Hugo on frog populations. Marliera sintensii, Ternstroemia luquillensis, and Xylosma schwaneckeanum.

Invertebrates Earthworn Study. -Monthly samplings of earth- FUTURE ACTMTIES worms were initiated in each of the Bdo de Oro's forest types in July 1991. The objectives of the project The Bafio de Oro is unique within the LEF and are to identify earthworm species and to determine if Puerto Rico. As witnessed by the rain forest life zones correlations exist between their occurrence and that characterize it, the Bafio de Oro is the wettest environmental factors. Soil pits measuring 25 by 25 cm tract in the LEF, which in turn is the wettest area in and 40 cm deep are being excavated at designated sites, Puerto Nco. The contiguous tract contains a good rep- and earthworm samples are being extracted from dif- resentation of all forest types undisturbed by humans, ferent depths. At each site, the date (season), altitude, albeit recently disturbed by Hurricane Hugo. Con- and loose litter above the pit are noted along with tinued human modification of forest land elsewhere in several soil parameters such as depth, humidity, bulk Puerto Rico may make the Baiio de Oro more valuable density, nutrient status, and organic matter content. with the passage of time. Studies of Other Organisms.-A free-living flat- The ecosystems represented are the products of cen- worm, roundworms, nematodes, and numerous mol- turies of evolution. The tract is sufficiently large to lusks and were identified in the survey of indefinitely support the flora and most of the fauna the Bdode Om (table 14). Much additional work needs that it contains under current climatic conditions. Cer- to be done with these groups of organisms. tain large such as the parrot, the broad- The nomenclature of the earthworms had not been winged hawk, and the tanager could not persist if this resolved at the time of the University of Puerto Rico area were managed in isolation. However, the entire survey. Moreover, the centipedes found in the Baiio de Bafio de Oro is surrounded by the LEF, which has been Oro could not be designated to corresponding families, protected for over a century. Deliberate modification, genera, or species because only one specimen of each such as extensive cutting, removal of plants or animals, was encountered and dissection is required before they or pollution of the waters, could have deleterious can be classified to family rank. identification of effects. In this respect, the Pico del Este road (Route Thysanoptera, Collembola, Orthhoptera, and others 930), which borders the Bafio de Om, represents a was also impossible. Study of the will take potential problem. Discarding of refuse or disturbance considerable time and, undoubtedly, involve many of roadside vegetation could become matters of concern investigators. as the forest receives more visitors. LITERATURE CITED Alvarez-Lopez, Migdalia. 1990. Ecology of Pterocarpus officinalis forested wetlands in Puerto Rico. In: The size, undisturbed nature, and diversity of the Lugo, Ariel E.; Brinson, Mark; Brown, Sandra, eds. Bario de Oro make it an ideal site for ecological investi- Ecosystems of the world. 15: Forested wetlands. gations. Soils range from deep alluviums in the narrow Amsterdam: Elsevier: 251-265. Chapter 10. valleys to shallow, rocky ridges. nYo life zones, four Alvarez Ruiz, Migdalia. 1982. A comparison of the major forest types, and the rare Pterocarpus swamp are structure and ecology of Pterocarpus officinalis found within the area or bordering it. Numerous tree (Jacq.) forested wetlands in Puerto Rico. Rio species, epiphytes, ferns, liverworts, and mosses char- Piedras, PR: University of Puerto Rico. 96 p. M.S. acterize the vegetation. The Puerto Rican parrot, the thesis. Puerto Rican tanager, the broad-winged hawk, and the Anthony, H.E. 1925-1926. Mammals of Porto Rico, boa constrictor add to the Baiio de Oro's diversity. living and extinct. In: Scientific survey of Porto Rico The Baiio de Oro is accessible from the Pico del Este and the Virgin Islands. New York: New York Acad- road at highest elevations and from the Bisley Trail and emy of Sciences: 1-238 (part 1,2). Vol. 9. the Big Treemio de la Mina trails at lowest elevations. Arendt, Wayne J. 1983. The effects of dipteran ecto- The Big Treemio de la Mina trail is particularly scenic, parasitism on the growth and development of nes- offering vistas of numerous waterfalls and exposed tlings of the pearly-eyed thrasher (Margarops rock along the river. From the standpoint of educa- fuscatus) in the Luquillo Mountains, Puerto Rico. tional opportunities, the fauna and flora of the moun- Columbia, MO: University of Missouri. 125 p. M.S. tains may be viewed more easily from other areas, thesis. suggesting that the Baiio de Oro should not be used Arendt, Wayne J. 1985a. Philornis ectoparasitism of intensively for this purpose. Moreover, adequate recrea- pearly-eyed thrashers. 1: Impact on growth and tional facilities already exist and will be amplified in development of nestlings. The Auk. 102: 270-280. other parts of the LEF; these areas have vistas and Arendt, Wayne J. 198513. Philnoris ectoparasitism of attractive watercourses like those of the Baiio de Om. pearly-eyed thrashers. 2: Effects on adults and The major uses of the Bat50 de Oro, then, should be for reproduction. The Auk. 102: 281-292. long-term ecological investigations. Many of the intriguing aspects of faunal and floral Bannister, Barbara A. 1970. Ecological life cycle of Euterpe globosa Gaertn. In: Odum, Howard T.; relationships in diverse habitats such as that of the Pigeon, Robert F., eds. A tropical rain forest. Spring- LEF cannot be answered without knowledge of past field, VA: U.S. Department of Commerce: 299-314. events. 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A study of the ecological life U.S. Department of Agriculture, Forest Service. 1990. history of Cecropia peltata L., an early secondary Draft: amended land and resource management successional species in the rain forest of Puerto plan: Caribbean National Forest/Luquillo Experi- Rico. Knoxville, TN: University of Tennessee. 94 p. mental Forest. Rio Piedras, PR: U.S. Department of M.S. thesis. Agriculture, Forest Service, Southern bgion and Smith, M.R. 1936. The ants of Puerto Rico. The Jour- Southern Forest Experiment Station. 6 chapters + nal of Agriculture of the University of Puerto Rico. appendices. 20(4): 819-875. Van der Schalie, Henry. 1948. The land and freshwater Smith, Robert F. 1970. Preliminary illustrated leaf key mollusks of Puerto Rico. Misc. Pub. 70. Ann Arbor, to the woody plants of the Luquillo Mountains. In: MI: Museum of Zoology, University of Michigan. 128 Odum, Howard T.; Pigeon, Robert F., eds. A tropical p. + plates. rain forest. 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Growth and age of Cyrilla ests of Puerto Rico and their destruction and conser- racemiflora L. in montane forests of Puerto Rico. vation prior to 1900. Caribbean Forester. 11: 38-47. Interciencia. ll(5):221-228. Wadsworth, Frank H. 1951. Forest management in the Weaver, Peter L. 1986b. Hurricane damage and recov- Luquillo Mountains. 1: The setting. Caribbean For- ery in the montane forests of Puerto Rico. Carib- ester. 12(3): 93-114. bean Journal of Science. 22(1-2): 53-70. Wadsworth, Frank H. 1952. Forest management in the Weaver, Peter L. 1989. Forest changes after hurricanes Luquillo Mountains. 3: Selection of products and in Puerto Rico's Luquillo Mountains. Interciencia. silvicultural policies. Caribbean Forester. 13: 93-119. 14(4): 181-192. Wadsworth, Frank H. 1970. Review of past research in Weaver, Peter L. 1990. Succession in the elfin woodland the Luquillo Mountains of Puerto Rico. In: Odum, of the Luquillo Mountains of Puerto Rico. Bio- Howard T.; Pigeon, Robert F., eds. 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The effect School of Forestry, Wildlife and Fisheries. 98 .p. of Hurricane Hugo on bat ecology with emphasis on Weathers, Kathleen C.; Likens, Gene E.; Bormann, F. an endemic Puerto Rican bat (Stenoderma rufum) Herbert [and others]. 1988. Cloudwater chemistry in the Luquillo Experimental Forest. Lubbock, TX: from ten sites in North America. Environmental Texas Technical University, Department of Biolog- Science & Technology. 22: 1018-1026. ical Science; research report. 30 p. Weaver, P.L.; Medina, E.; Pool, D. [and others]. 1986. Wolcott, George N. 1923. Insectae Portoricensis. Jour- Ecological observations in the dwarf cloud forest of nal of Agriculture of Porto Rico. 7(2): 1-312. the Luquillo Mountains. Biotropica. 18: 79-85. Wolcott, George N. 1936. Insectae Borinquensis. Jour- Weaver, Peter L. 1972a. Cloud moisture interception in nal of Agriculture of the University of Puerto Rico. the Luquillo Mountains of Puerto Rico. Caribbean 20(1): 1-627. Journal of Science. ll(3-4): 129-144. Wolcott, George N. 1948. The insects of Puerto Rico. Weaver, Peter L. 1972b. The dwarf forest of Pico del Journal of Agriculture of the University of Puerto Este and the Luquillo Mountains. Revista Inter- Rico. 32:(1): 1-975. americana. 2(2): 174-186. Woodbury, Roy; Raffaele, Herbert; Fram, Mitchell [and Weaver, Peter L. 1975. Transpiration rates in the elfin others]. 1975. Rare and endangered plants of Puerto forest of the Luquillo Mountains of Puerto Rico. Rico: a committee report. San Juan, PR: U.S. Caribbean Journal of Science. 15(1-2): 21-30. Department of Agriculture, Soil Conservation Ser- Weaver, Peter L. 1983. Tree growth and stand changes vice and Commonwealth of Puerto Rico Department in the subtropical life zones of the Luquillo Moun- of Natural Resources. 85 p. tains of Puerto Rico. Res. Pap. SO-190. New Orleans, Zwank, Phillip J.; Walker Layton, Benjamin. 1989. LA: U.S. Department of Agriculture, Forest Service, Black rats as potential Puerto Rican parrot nest Southern Forest Experiment Station. 24 p. predators. Caribbean Journal of Science. 25(1-2): 13-20. Appendix Tkble 1.-Select reference list for flora and fauna in Puerto Rico including the Barb de Om Natural Area Topics Soums

Vegetation Forest types Beard 1944, 1949; Dansereau and Buell 1966; Ewe1 and Whitmore 1973; Little and others 1974; Little and Wadsworth 1991; Stehle 1945; Wadsworth 1951

Botany Britton and Wilson 1923-30a, 1923-3Ob; Cook and Gleason 1928; Gleason and Cook 1927; Howard 1968

Trees 1Seedlings Duke 1970, Little 1970, Little and others 1974, Little and Wadsworth 1991, Little and Woodbury 1976, Longwood 1961, Smith 1970

Autecology (trees) Bannister 1970; Burns and Honkala 1990f;Edmisten 1970; Francis, in press*;Frangi and Lugo 1985; Lebron 1977; Mufiiz-Melendez 1978; Nieves 1979; Sastre de Jesus 1979; Silander 1979; Van Valen 1975; Weaver 1986b

Phenology (trees) Estrada Pinto 1970, Nwling 1971

Ferns Kepler 1975, Proctor 1989

Medicinal plants Nunez Melendez 1982

Bryophytes Crum and Steere 1957; Word and others 1970, 1971; Gradstein 1989; Miller and Russel 1975; Russel and Miller 1977

Mycology Seaver and Chardon 1926, Seaver and others 1926

Lichens Harris 1989

Myxomycetes Alexopoulos 1970

Animals Mammals Anthony 1925-26, Starrett 1962, Wsitt and Valdivieso 1970

Biaggi 1970; Bond 1971; Danforth 1931; Leopold 1963; Raffaele 1983; Wetmore 1916, 1927; Wiley and Bauer 1985

AmphibiansIReptiles Drewry 1970a, Rand 1964, Rivero 1978, Schmidt 1928, Stejneger 1904, Thomas 1966

Insects Barber 1939; Comstock 1944; Curren 1928; Drewry 1970b; Forbes 1930,1931; Klots 1932

Spiders Martorell 1945; Osborn 1935; Petrunkevich 1929, 1930; Schauss 1940; Smith 1936; Wolcott 1923,1936,1948

Mollusks Aguayo 1966, Van der Schalie 1948

Rare / Sensitive Species Proctor 1991, RafTaele and others 1977, USDA FS 1990, Woodbury and others 1975

*Contains descriptions of 20 tree species native or introduced to Puerto Rico. tContai1-t~descriptions of 71 tree species to date, many of them introduced to Puerto Rico. The United States Department of Agriculture (USDA) prohibits discrimina- tion in its programs on the basis of race, color, national origin, sex, religion, age, disability, political beliefs, and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720-5881 (voice) or (202) 720-7808 (TDD). To file a complaint, write the Secretary of Agriculture, U.S. Department of Agriculture, Washington, DC 20250, or call (202) 720-7327 (voice) or (202) 720-1 127 (TDD). USDA is an equal employment opportunity employer. Weaver, Peter L. 1994. Baiio de Oro Natural Area, Luquillo Mountains, Puerto Rico. Gen. Tech. Rep. SO-111. New Orleans, LA: U.S. Depart- ment of Agriculture, Forest Service, Southern Forest Experiment Station. 55 p.

Past and current research in the Baiio de Oro Natural Area is summa- rized and used as a basis for further investigation. The current state of knowledge regarding the environment is outlined.

Keywords.. Climate, fauna, flora.